Showing papers in "Aquatic Conservation-marine and Freshwater Ecosystems in 2011"

Declines in the tuber‐feeding waterbird guild at Shengjin Lake National Nature Reserve, China – a barometer of submerged macrophyte collapse

Abstract: 1. The Yangtze floodplain is globally unique for its extensive ephemeral wetlands, recharged by summer monsoon precipitation. The annual cycle of inundation and water table recession favours submerged macrophytes, including Vallisneria that overwinters in desiccated substrates as tubers, which provide high-energy winter food for tuber-feeding waterbirds that were formerly abundant in the region. 2. Large declines among the tuber-feeding waterbirds swan goose Anser cygnoides (L.), tundra swan Cygnus columbianus (Ord) and hooded crane Grus monacha Temminck between 2004/2005 and 2009/2010 at Shengjin Lake, Anhui Province, suggest that major changes in food availability have occurred there. 3. Based on observations of feeding behaviour and energy budgets of these species, it was calculated that at least 5.0 and 8.9?km2 of Vallisneria beds in 2004 and 2005, respectively, would be needed to support observed numbers of these species, compared with less than 1.5?km2 found in 2009 and 2010. 4. An incomplete macrophyte survey in summer 2000 located at least 7.7?km2 of Vallisneria beds in the Upper Lake, where none was present during resurveys in 2008 and 2009. Declines in tuber-feeding waterbirds at Shengjin Lake coincide with the disappearance of their submerged macrophyte food plants, possibly as a result of eutrophication since the mid-2000s. 5. Widespread declines and concentration of tuber-eating wintering waterbirds at other sites elsewhere in the Yangtze floodplain may also reflect the local collapse of submerged macrophytes and of ecosystem services that these wetlands provide to the human communities.

A critical reflection on the success of rearing and culturing juvenile freshwater mussels with a focus on the endangered freshwater pearl mussel (Margaritifera margaritifera L.)

Abstract: Freshwater mussels are in decline throughout their range. The lack of natural recruitment in freshwater pearl mussel populations and other freshwater molluscs has led to controversies about the usefulness and applicability of captive breeding techniques for their conservation. The current state of rearing and culturing programmes for freshwater mussels in Europe and North America is reviewed here with a focus on the endangered freshwater pearl mussel (Margaritifera margaritifera). Different strategies of propagation and the key factors of success are addressed and conservation management decisions are discussed with respect to risk reduction and the intensity of the culturing system. Based on the rearing techniques applied for multiple species in North America, and for the genus Margaritifera in European countries, sufficient numbers of juveniles can be produced to sustain selected populations. However, captive breeding and stocking should be carefully documented and must not replace the restoration of functional stream habitats. From a conservation point of view, captive breeding of endangered mussel species can be a last-minute rescue tool in order to retain the evolutionary potential of priority populations which would not persist long enough to benefit from habitat restoration practices. Copyright © 2011 John Wiley & Sons, Ltd.

Distribution, abundance, and movements of the bottlenose dolphin (Tursiops truncatus) in the Pelagos Sanctuary MPA (north‐west Mediterranean Sea)

Abstract: The Pelagos Sanctuary is the largest marine protected area of the Mediterranean Sea (87 500km 2 ), and is located in the north ! west part of the basin. The presence of the bottlenose dolphin in this area is well documented but its distribution and abundance are not well known. 2. The present study collected and analysed data from 10 different research groups operating in the Pelagos Sanctuary from 1994 to 2007. Photo ! identi !cation data were used to analyse the displacement behaviour of the dolphins and to estimate their abundance through mark " recapture modelling. 3. Results show that the distribution of bottlenose dolphin is con !ned to the continental shelf within the 200m isobath, with a preference for shallow waters of less than 100m depth. 4. Bottlenose dolphins seem to be more densely present in the eastern part of the sanctuary and along the north ! west coast of Corsica. 5. Bottlenose dolphins show a residential attitude with excursions usually within a distance of 80km (50km on average). A few dolphins exhibit more wide ! ranging journeys, travelling up to 427km between sub ! areas. 6. The displacement analysis identi !ed two (sub)populations of bottlenose dolphins, one centred on the eastern part of the sanctuary and the other one around the west coast of Corsica. 7. In 2006, the eastern (sub)population was estimated to comprise 510 " 552 individuals, while 368 " 429 individuals were estimated in the Corsican (sub)population. It was estimated that in total, 884 " 1023 bottlenose dolphins were living in the Pelagos Sanctuary MPA in the same year. 8. The designation ofa number ofSpecial AreasofConservation(SACs) under theHabitats Directiveisdiscussed asapossibletooltoprotectthebottlenosedolphininthePelagosSanctuaryandinthewholeoftheMediterraneanSea. Copyright # 2011 John Wiley & Sons, Ltd.

Applications and future challenges in marine species distribution modeling

Abstract: 1. Anthropogenic climate change affects both phenology and distribution patterns of the world's biota including marine species. During the last decade, species distribution models have been more frequently used to assess the potential distributions of species and possible effects of climate change. However, unlike for terrestrial species, there have been few investigations assessing climate change effects on distribution patterns of marine organisms. 2. An overview of marine species distribution modelling is given. Possibilities of how to characterize and project the environmental niches of species onto climatic change scenarios are highlighted and novel techniques for addressing specific needs in a 3-D context are proposed. A detailed introduction into different modelling tools and databases for environmental parameters given provides a starting point for the application of these models. 3. Application of a species distribution model and its projections onto a glacial and future scenario on a global scale are presented for the great white shark (Carcharodon carcharias) for illustrative purposes. An approach for addressing marine migratory species with seasonal distribution patterns is presented. Copyright © 2010 John Wiley & Sons, Ltd.

Biodiversity value of agricultural drainage ditches: a comparative analysis of the aquatic invertebrate fauna of ditches and small lakes

Abstract: 1. Drainage ditches are a common aquatic habitat in the lowland agricultural landscape of north-western Europe. The invertebrate fauna of these waters is poorly known compared with that of the semi-natural wetland fragments found in this region. While most wetlands are designated as nature reserves, drainage ditches are generally viewed purely as hydrological infrastructure in support of agriculture. 2. To assess the conservation value for aquatic invertebrates of these man-made habitats compared with that of wetland fragments, the taxonomic composition and life-history characteristics of invertebrate assemblages inhabiting nine small lakes and nine ditches in peatlands in the Netherlands were compared, as well as the environmental characteristics potentially influencing assemblage structure. 3. Although ditches comprised a smaller water volume, contained less diverse vegetation, displayed larger fluctuations in nutrient concentrations and were regularly managed, the total number of invertebrate taxa recorded per taxonomic group was comparable with that in small lakes, as was the number of nationally uncommon to very rare taxa. 4. Similarity in life-history characteristics between the two water-body types was high, except that a higher proportion of atmospheric air breathers was found in ditches, and more plant miners and collector–filterers in small lakes. 5. On a regional scale, a relatively high inter-ditch taxon dissimilarity was observed, resulting in total diversity estimates for ditches exceeding those of small lakes. 6. This study showed that drainage ditches can be a significant habitat type for aquatic invertebrates. In the Netherlands, water bodies in peatland agricultural areas can contain a diverse invertebrate fauna, similar to that of water bodies in nearby nature reserves.

Recreational angling markets to advance the conservation of a reach of the Western Ramganga River, India.

Abstract: 1. Mahseer fishes of the genus Tor are 'iconic species' in Indian rivers, representing 'flagship' species for conservation purposes but with additional exploitable, cultural and economic values. Conservation action is required to address their vulnerability to numerous pressures on multiple habitats, and connections between them, across the extended aquatic ecosystems supporting different life stages. 2. Recreational angling for mahseer, along with associated wildlife and cultural tourism, is a growth industry dependent upon healthy river ecosystems. 3. A cyclic, ecosystem-based model in which local people can benefit economically from sustainable mahseer exploitation through catch-and-release fisheries can form a basis for conservation of both mahseer and the wider river ecosystem. 4. Experience on the Western Ramganga River in the vicinity of the town of Bikhyasen, Uttarakhand State (in the Himalayas in northern India), demonstrates the importance of involving local people in the benefits associated with angling, wildlife and cultural tourism. This creates local incentives for river protection, and may be the most effective means for preventing destructive over-exploitation in poor rural communities. 5. Recognition of this value and its recirculation to local people can form the basis for a 'paying for ecosystems services' (PES) market. This will benefit river ecosystems, local people, tour operators and visiting anglers, provided that local people benefit to a greater extent than through the killing of fish for non-renewable consumption or sale. 6. This is the basis for a potentially transferable model which may support regional development through involving local people in markets for iconic species. © 2010 John Wiley & Sons, Ltd.

Testing a depth-based Habitat Classification System against reef fish assemblage patterns in a subtropical marine park

Abstract: 1. The Solitary Islands Marine Park (SIMP) in New South Wales (NSW), Australia, has strong cross-shelf patterns of reef fish assemblages on shallow reefs ( 60 m). However, these had not been tested to determine if they adequately reflect biotic patterns. 2. Using baited remote underwater video (BRUV), fish assemblages were surveyed at 56 sites spread across shallow, intermediate, and deep reefs within the SIMP to examine spatial variation between depth categories. Relationships between assemblage patterns, depth, and four additional factors considered likely to affect assemblage patterns (distance from shore, reef type, dominant benthos, and latitude), were subsequently explored using multivariate statistical methods. 3. Reef fish assemblages differed significantly among the depth categories. Assemblage patterns for fish were strongly correlated with depth and moderately correlated with the dominant benthic assemblage. Correlations with the other factors were generally weak. Three distinct assemblages occurred on reefs 50 m. Shallow (<25 m) reefs also displayed strong cross-shelf patterns, supporting the results from other studies. Weaker cross-shelf patterns were evident at intermediate depths (25–50 m). 4. Depth-based and cross-shelf categories are clearly fundamental components for a HCS that will adequately represent reef fish assemblages for conservation planning in the SIMP. Further refining the depth criteria for the intermediate/deep boundary (to 50 m) improves this representation. Further research is required to determine the wider application of the refined HCS to other marine parks in NSW and to determine how well it represents other components of biodiversity. Copyright © 2011 John Wiley & Sons, Ltd.

Does the global network of marine protected areas provide an adequate safety net for marine biodiversity

Abstract: COMMENTARY As recognized in the 2020 Strategic Plan for the Conservation of Biological Diversity,1 which was recently agreed at the Convention of Biological Diversity in Kyoto, the global marine protected area (MPA) network is far from comprehensive. In a recent review,Wood et al. (2008) identified a globalMPA network covering 2.35million km2 (0.65% of the world’s oceans and 1.6% of the total marine area within Exclusive Economic Zones), but with only 0.08% of the world’s oceans highly protected within ‘no- take’ zones. With the recent declaration of large protected areas around the Phoenix Islands and Chagos Archipelago, the total area has increased since that review; nevertheless, no more than 1% of the sea surface is currently included within MPAs (Cullis-Suzuki and Pauly, 2010), with a much smaller proportion (probably <0.1%) included within the fully protected ‘no-take’ subset. The area of sea protected at the highest level for conservation – ‘no-entry’ zones – is minute (<0.001%). Moreover, a need for better protection of species’ populations extends to even the most highly reserved regions. For example, none of 13 recently declaredMPAswithin theBruny bioregion off south-eastern Tasmania contains individuals of the spotted handfish Brachionichthys hirsutus (Last et al., 2007), a Critically Endangered species confined to that bioregion and with a total population numbering less than 10 000 individuals. Populations of many marine species, particularly those with limited ranges, lack any overlap with well-protected MPAs. More debatable than the issue of comprehensiveness is the adequacy question: ‘Do existing MPAs adequately safeguard biodiversity within their boundaries’. Much of the difficulty in answering this question relates to a near absence of empirical studies specifically directed at the topic. In a recent (22 February 2011) literature search using SCOPUS with the search string (‘marine protected area’ or ‘marine reserve’) and ‘threatened species’, only 23 papers were identified, compared with a total of 951 papers identified for the search string (‘marine protected area’ or ‘marine reserve’) and ‘fisher’. Assuming that the primary indicator of declining biodiversity is loss of species, and that species recognized as threatened provide a predictive metric for species loss, then the ~40:1 ratio betweenMPApapers mentioning threatened species and those mentioning fishers or fisheries is broadly indicative of relative research effort on the two topics. In fact, the true situation is even more unbalanced given that the 23 MPA papers that mentioned ‘threatened species’ were largely review papers, and none used directed field data to specifically answer the question ‘Do MPAs benefit one or more threatened species?’

Degradation of the crocodile population in the Olifants River Gorge of Kruger National Park, South Africa

Abstract: 1.Top predators such as crocodiles often reflect ecosystem degradation. The recent spate of close to 200 Nile crocodile deaths may reflect the ecosystem state of the Olifants–Letaba River system in the Kruger National Park. This paper investigates whether the crocodile deaths were indeed the consequence of a rare and perhaps acute event given the variability in annual population growth rates of crocodilians. 2.Spotlight- and helicopter-based surveys designed to correct for availability and detectability bias were used to estimate population sizes of crocodiles from 2008 to 2010 in and around the Olifants River Gorge, the focal area of crocodile deaths. 3.Correction factors derived from individually observed crocodiles for both spotlight- and helicopter-based counts were lower than those typically used for Nile crocodiles as well as other crocodile species. Even so, corrected spotlight- and helicopter-based estimates were comparable and the number of crocodiles in the focal study area declined significantly from 780 (95% CI: 637–1222) to between 460 (spotlight estimate, 95% CI 375–665) and 505 (aerial estimate, 95% CI: 559–1746) during the period of crocodile deaths. The average annual decline of 35% was at the lower end of the distribution of annual population growth rates across the rivers of Kruger National Park. 4.The crocodile deaths reflect a possible rare event that suggests a degraded crocodile population, possibly the consequences of broad-scale cascades of environmental deterioration of the Olifants–Letaba River system. 5.Even so, the potential risk of local demise of the population in the focal study area in the short term may be diminished through evolutionary, demographic and spatial resilience inherent within crocodiles that can accommodate the as yet unknown disease dynamics of pansteatitis. Copyright © 2011 John Wiley & Sons, Ltd.

Development and evaluation of a fish-based index to assess biological integrity of Mediterranean streams

Abstract: Additional funding was provided by the Spanish Ministry of Science (CGL2009‐12877‐C02‐01 and Consolider‐Ingenio 2010 CSD2009‐00065)

The conservation status of Sabellaria alveolata (L.) (Polychaeta: Sabellariidae) reefs in the Bay of Mont‐Saint‐Michel

Abstract: 1. Reefs built by the annelid worm Sabellaria alveolata in the Bay of Mont-Saint-Michel (France) are the most extensive intertidal biogenic structures within Europe. Before and after mussel farming extensions, a study designed to provide a biological health index of the Sainte-Anne reef (223 ha) was carried in 2001 and 2007 to serve as an easy-to-use management tool and to ensure endangered reef portions were properly targeted and protected. 2. Coupled physical and biological parameters were included in a spatial Health Status Index (HI). A spatial and temporal mapping survey of the HI showed a continuous deterioration of the reef's state of health, particularly in its central part. This degradation correlates with the colonization of the Pacific oyster Crassostrea gigas and with increasing silt deposits on the reef. 3. A combination of several factors is likely to explain such rapid reef deterioration: (1) an increase in trophic competition between cultivated and wild suspension-feeders that is detrimental to the annelids; (2) a modification in the hydrodynamics and consequently in sedimentary patterns leading to an increase in silt deposition; and most importantly (3) an increase in recreational harvesting of oysters and associated reef trampling, resulting in reef fragmentation. 4. Understanding the parameters that influence the reef dynamics is necessary in order to help efficient and effective management and policy focusing on the conservation status of large biogenic structures. Copyright (C) 2011 John Wiley & Sons, Ltd.

Salinity tolerance of non-native suckermouth armoured catfish (Loricariidae: Pterygoplichthys) in south-eastern Mexico: implications for invasion and dispersal

Abstract: Salinity tolerance is one of several important physiological attributes that determine invasion success and the pattern of dispersal of introduced aquatic organisms. Introduced freshwater fishes able to tolerate elevated salinities have the potential to invade and exploit brackish-water (mixohaline) environments and use estuaries and coastal waters as ‘bridges’ for dispersing from one coastal river system to another. Several members of the neotropical suckermouth armoured catfish genus Pterygoplichthys (Siluriformes: Loricariidae) have established non-native populations in inland waters of North and Central America, Asia and islands in the Caribbean, and Pacific and Indian oceans. Loricariids are generally considered to be strictly freshwater; but a few naturally occur in mesohaline habitats. Catch and habitat data from 2004–2005 and 2009–2011 fish surveys in the Grijalva–Usumacinta River delta region (south-eastern Mexico) confirmed that introduced Pterygoplichthys populations established in upstream freshwater sites (where these catfish are abundant) have recently dispersed into downstream oligohaline and mesohaline estuarine habitats. During 2009–2011 surveys, these non-native catfish – tentatively identified as P. pardalis or its hybrids – were found in sites with salinities ranging from 1 to 8 ppt (mean 5.2 ppt). Acute-salinity experiments were conducted with Pterygoplichthys (110–302 mm standard length, N = 140) captured in the Grijalva–Usumacinta Basin to determine upper salinity tolerance levels. Tests demonstrated that individuals maintained in salinities of 0.2 ppt were able to survive abrupt (acute) exposure to salinities up to 10 ppt with little mortality over 10 days (240 h experimental endpoint). A few individuals survived abrupt exposure to 11 and 12 ppt for 20 or more hours, although none survived more than a few hours at 16 ppt or greater. These field and experimental results provide quantitative evidence that non-native Pterygoplichthys are physiologically capable of surviving mesohaline conditions for extended periods and that non-native populations in Mexico are invading and presumably exploiting estuarine and other coastal environments, perhaps as feeding areas and potentially as dispersal routes. Copyright © 2011 John Wiley & Sons, Ltd.

Shelf‐edge reefs as priority areas for conservation of reef fish diversity in the tropical Atlantic

Abstract: 1.Data from fishing surveys employing bottom long-lines were analysed to characterize the diversity, assemblages and distribution patterns of demersal fish along the Brazilian outer shelf and upper slope, between latitudes 13°S and 22°S. 2.Non-metric multi-dimensional scaling (MDS) and cluster analysis indicate three distinct species assemblages separated primarily by depth (the 200 m isobath) and secondarily by latitude (19°S), suggesting a continual transition along the depth and latitudinal gradients in the study area. Species richness was negatively correlated with depth, but with no clear relationship with latitude. 3.Results suggest the existence of reef formations on the shelf-edge zone (40–200 m) and slope down to 500 m depth off the eastern Brazilian coast. More than 75% of the catches recorded were reef fish species from the families Serranidae, Lutjanidae, Malacanthidae, Muraenidae, Sparidae, Balistidae, Carangidae, Haemulidae, Scorpaenidae and Priacanthidae. 4.The maximum depth of occurrence for 20 reef species was extended from limits previously recorded. 5.The findings reinforce the hypothesis of a faunal corridor for species associated with deep reef formations along the shelf-edge zone (40–200 m), in the South American continental margin, connecting the south-western Atlantic and the Caribbean provinces. 6.The shelf-edge reefs support important multi-species fisheries and harbour critical habitats for the life cycle of many reef fish species, including spawning aggregation sites that are extremely vulnerable to human pressures, such as intensive fishing, shipping and offshore oil and gas exploitation; all activities currently expanding off the Brazilian coast. 7.Results reveal the biological importance of deep shelf-edge reefs as a critical ecological area. Despite their importance, shelf edge reefs are not currently included in any marine protected area network in the tropical south-western Atlantic. There is now an urgent need to enhance knowledge, implement adequate management strategies and consider these deeper habitats as priority areas for conservation. Copyright © 2011 John Wiley & Sons, Ltd.

Population assessment and potential functional roles of native mussels in the Upper Mississippi River

Abstract: Despite a heightened global concern for native mussels, fundamental research on mussel ecology in large rivers is lacking. These gaps in knowledge about where mussels occur, and why, are limiting habitat restoration activities. 2. Large-scale systematic surveys for native mussels in three reaches of the Upper Mississippi River documented mussel communities composed of 16-23 species and ranging from 2.9-4.5 live mussels m � 2 that were actively recruiting new cohorts into their populations (87-100% of the species were found as juveniles p5 years old). Estimates of mean tissue biomass and production in these reaches ranged from 2.1-3.1 g C m � 2 and 0.4-0.6 g C m � 2 year � 1 , respectively. 3. Mussels filtered a significant amount of water (range, 0.05-0.07 m 3 m � 2 d � 1 ) over a 480 km reach of the Upper Mississippi River - amounting to a filtration rate of 53.1 million m 3 day � 1 . The filtration rate of mussels as a percentage of river discharge ranged from 0.5-1.4% at high flows (5% exceedance), from 1.5-4.4% at moderate flows (50% exceedance) and from 4.4-12.2% during low flows (95% exceedance). 4. Collectively, these data suggest that native mussels play an integral role in this ecosystem by sequestering suspended materials that can be used by other benthic organisms. Published in 2011 by John Wiley and Sons, Ltd. Received 17 June 2010; Revised 20 December 2010; Accepted 21 December 2010

Dolphins and coastal fisheries within a marine protected area: mismatch between dolphin occurrence and reported depredation

Abstract: 1. Dolphins are often blamed for reducing fisheries catches and may be killed in retaliation. Depredation of fishing gear in coastal Mediterranean waters is normally caused by bottlenose dolphins. Economic impact, however, may be modest even within areas of reportedly acute conflict. 2. Boat surveys and interviews were conducted to investigate dolphin occurrence and interactions with fisheries within the 167 km2 Porto Cesareo Marine Protected Area (MPA) in southern Italy. Based on 69 interviews with fishermen using bottom-set trammel and gill nets, there was reportedly a high occurrence of depredation by bottlenose dolphins. Depredation was reported by 92% of the fishermen operating in or near the MPA, and 67% of them claimed an economic cost in excess of €1000 per year, with a mean reported cost of €2561: a higher impact than in other Mediterranean studies. 3. According to local fishermen, dolphin occurrence and depredation peaked in spring and autumn, coincident with the study's surveys at sea. Dedicated visual surveys totalling 1255 km of effort, however, resulted in no encounters with cetaceans. Information from interviews and boat surveys was therefore contradictory, suggesting that reports of acute depredation do not imply a constant presence of dolphins within the MPA. 4. While depredation in the MPA might be caused by wide-ranging dolphins or incursions occurring overnight, damage may well be overestimated or over-reported. As local fishermen had previously benefited from subsidies, interviews made during this study could be perceived by some as an opportunity to influence future decision-making regarding monetary compensation for the impact of depredation. 5. Evidence from interviews also indicated that species and factors other than dolphins were responsible for part of the damage. Copyright © 2011 John Wiley & Sons, Ltd.

Manipulating artificial habitats to benefit seahorses in Sydney Harbour, Australia

Abstract: Artificial habitats are a common feature of urban marine environments and usually support different assemblages of marine organisms in contrast to neighbouring natural habitats Despite these differences, artificial habitats can be managed to benefit biodiversity, either by the addition of structures to provide habitat where little natural habitat remains, or by engineering existing structures to better support native populations 2 Seahorses are listed as protected species in New South Wales, Australia, and are of conservation concern worldwide The physical structure of nets used to protect popular swimming beaches in a highly urbanized estuary, Sydney Harbour, was manipulated to test the hypotheses that more structurally complex habitats would support higher abundances of the seahorse Hippocampus whitei that use these structures and their potential prey (mobile crustaceans) 3 The simple addition of frayed net material to construct a more structurally complex net habitat supported higher abundances of H whitei than unmanipulated nets in a field experiment over 53 days Habitat preference assays in the laboratory supported the hypothesis that the patterns of distribution observed in the field were due to the preferences of individual seahorses for the more complex habitats 4 The habitats manipulated to add structural complexity supported much higher abundances of the mobile epifauna (amphipods, copepods) that are consumed by seahorses The potential therefore exists to engineer artificial structures in urban estuaries to provide habitats that are preferred by vulnerable fauna and their food sources Copyright # 2011 John Wiley & Sons, Ltd

Conservation of Mediterranean habitats and biodiversity countdowns: what information do we really need?

Abstract: 1. The relentless increase in both human activities and exploitation of marine resources is a threat to marine habitats and species. 2. For marine systems, several protection initiatives have been outlined over the past decade to significantly reduce the current rate of biodiversity loss at global, regional, and national levels, and to establish representative networks of marine protected areas with the aim of protecting 10–30% of marine habitats. 3. Reliable estimates of the total area occupied by each habitat are crucial to set adequate protection initiatives. Habitat mapping requires a sound habitat classification. Many classification schemes have been developed in different areas of the world, sometimes based on questionable criteria. 4. A critical analysis of the most recent marine habitat classification list produced for the Mediterranean Sea from the Regional Activity Centre for Specially Protected Areas (RAC/SPA) showed that (i) 39% of habitats and associated species considered in the list are scarcely covered by scientific knowledge from Web-based resources; (ii) 62% of the species/genera included in the list are primary producers; (iii) quantitative information about the geographical distribution of selected habitats and associated species is scant; and (iv) when available, information is largely unbalanced and biased towards the shallow western Mediterranean Sea. 5. Improved inventories of marine habitats are needed to support accurate and consistent mapping activities. The combination of large-scale mapping and sound habitat classifications will allow better estimates of biodiversity distribution, to reverse regional/global habitat loss rates through the achievement of conservation targets and deadlines that, for the moment, are systematically not met. Copyright © 2011 John Wiley & Sons, Ltd.

Effects of modern drainage systems on the spatial distribution of loach in rice ecosystems

Abstract: 1. Although rice fields support many aquatic species, recent agricultural intensification in Asia has led to loss of biodiversity, such as freshwater fish, in exchange for increased agricultural productivity. In Japan, modern drainage systems have been introduced in recent decades. 2. This study investigated the effects of several aspects of modern drainage systems on the spatial distribution of dojo loach Misgurnus anguillicaudatus, a dominant fish species in Japanese rice fields. 3. Multimodel inference approaches and hierarchical partitioning were used to estimate the direction and degree of the effect of each system on the spatial distribution of dojo loach. 4. Three variables related to modern drainage systems (gaps between fields and ditches, the type of drainage ditch, and the presence of underground drainage pipes), flooding dates, and spatial autocovariates showed significant influence on the abundance of loach. In particular, gaps had the largest impact among all the variables on loach in the later part of the survey (June). 5. Based on the results, the effectiveness of several conservation methods implemented for paddy-dwelling fish in Japan was discussed. The knowledge will be a guide to the appropriate conservation of freshwater fish in Asia and other countries.

Spillover effects of a Mediterranean marine protected area on the European spiny lobster Palinurus elephas (Fabricius, 1787) resource

Abstract: An assessment is made of the reserve's benefits within the no-take area of Su Pallosu (Western Mediterranean) and in its neighbouring fishing ground in the 12 years since its establishment. Using tag recapture data, Palinurus elephas were found up to 50 km from the centre of the reserve. Experimental CPUE inside the no-take area indicated significant increases over time in both abundance and biomass. The percentage increase in biomass from 1997, the year before all forms of fishing were banned, to 2009 was about 500%. Commercial surveys performed in 2008–2009 in the surrounding areas showed a negative gradient of lobster CPUE with increasing distance from the border of the MPA. The most productive zone was located within about 6 km from the reserve boundary. The results show that, to date, adult spillover has aided local fishing. The small size of the study area makes it easy to record a significant biological response after the first year of protection. However, for a long-lived species such as P. elephas, a 12 year horizon can provide only partial evidence of these benefits. Copyright © 2011 John Wiley & Sons, Ltd.

Influence of life-history variation on demographic responses of three freshwater mussel species (Bivalvia: Unionidae) in the Clinch River, USA

Abstract: 1. Variation in age, shell growth, and demographic responses of two endangered mussel species, Epioblasma brevidens and Epioblasma capsaeformis, and a third non-listed species, Lampsilis fasciola, were studied from 2004–2008 in a 32-km reach of the Clinch River, TN. 2. Observed maximum age and length of E. brevidens was 28 yr and 71.5 mm for males and 15 yr and 56.6 mm for females; of E. capsaeformis, 12 yr and 54.6 mm for males and 9 yr and 48.6 mm for females; and of L. fasciola, 45 yr and 91.3 mm for males and 24 yr and 79.8 mm for females. 3. Estimated population size was ∼46 000 individuals for E. brevidens, ∼862 000 individuals for E. capsaeformis, and ∼33 000 individuals for L. fasciola. 4. Mean recruitment per year of 1 yr-olds ranged from 12.0% to 24.0% for E. brevidens, 4.2% to 56.6% for E. capsaeformis, and 10.0% to 38.5% for L. fasciola, and mean annual population growth rate was 21.0%, 31.3%, and − 24.3%, respectively. 5. Juveniles were detectable but temporally and spatially variable in occurrence, and a significant proportion of the age-class structure of each species. Recruitment was exceptionally high for E. capsaeformis during years when discharge was low in spring and summer. 6. Population size, growth, recruitment, and mortality rates of the shorter-lived E. capsaeformis were correspondingly higher than those of E. brevidens and L. fasciola. 7. The federal recovery plan for E. brevidens and E. capsaeformis identifies quantification of demographic variables as a critical step toward meeting the recovery needs of each species. The data collected in this study begin to meet these needs and can be used to monitor and evaluate population performance of each species. Published in 2011 by John Wiley & Sons, Ltd.

Potential impacts of non-native channel catfish on commercially important species in a Japanese lake, as inferred from long-term monitoring data

Abstract: Biological invasions are among the most serious threats to freshwater biodiversity. Analysis of long-term data can be a positive first step toward properly identifying the ecological and economic damage caused by invasive species. This study assessed the potential impacts of invasive channel catfish (Ictalurus punctatus), which have multiplied dramatically since around 2000 in Lake Kasumigaura, Japan, on native fish and shrimp and the commercial fishery using fishery-independent, quantitative long-term monitoring data (1993–2007). Temporal changes in abundance of 17 native fish species and one native shrimp species were analysed, and their sensitivity was evaluated, measured as change in relative abundance to the increase in I. punctatus abundance, was evaluated. A trait analysis of 18 species was performed in an attempt to investigate biological traits related to a negative sensitivity to I. punctatus invasion. After controlling for the effect of trophic status (total nitrogen and total phosphorus), nine of the 18 native species declined significantly through time and showed negative sensitivity to the increase in I. punctatus abundance; these included all four species used as raw materials for Japanese traditional processed foods. The trait-based analysis also revealed that benthic species and/or the species with a narrow diet range have decreased in abundance with increasing I. punctatus abundance. This suggests that competition for food, rather than predation by I. punctatus, is an important mechanism that results in a negative impact on native species. This study suggests that I. punctatus invasion may change the native community composition and negatively influence commercially important species, leading to a reduction in the provision of ecosystem goods. Copyright © 2011 John Wiley & Sons, Ltd.

Testing for top-down control: can post-disturbance fisheries closures reverse algal dominance?

Abstract: The response of fish, sea urchins, benthic cover, herbivory, and predation on sea urchins were studied over a 14-year period in and out of a recently established fully closed and fished atoll reef lagoon of the remote Glover's Reef, Belize. Closure from fishing was predicted to result in the recovery of predatory fish and herbivores, herbivory rates, and subsequently reduce erect algae and lead to the recovery of herbivore resistant and calcifying taxa such as hard corals and calcifying algae. Recovery of predatory fishes was the largest response to closure and the herbivore response was weak and no corals and calcifying algae changed in the predicted direction. Hard corals declined where they were most abundant and all sites appear to have reached a stable point of ~15% cover by the end of the study. Generalized and possibly opportunistic carnivores, such as jacks, barracuda, groupers, snappers, grunts, and sparids showed the greatest increases and there was a trend towards more small-bodied herbivores such sea urchins and damselfish in the open and a slight gain in large herbivores in the closed area, but this had little effect in increasing total herbivory. Factors that may have influenced this unexpected response include: (1) a complex food web that did not produce a simple cascade response; (2) attenuation of the cascade effect towards the lower trophic levels; (3) insufficient compliance, closure time, and space; (4) a post- rather than pre-disturbance establishment of the closure; 5) habitat or site specificity; and (6) overriding environmental disturbances, such as oceanographic oscillations and a warming climate. The results suggest a need to further evaluate fisheries management systems, contingencies, and interventions that will promote coral reef resilience to climate change and ecosystem sustainability. Copyright © 2011 John Wiley & Sons, Ltd.

Biological implications of recreational shore angling and harvest in a marine reserve: the case of Cape Creus

Abstract: This study was funded by the Natural Park of Cap de Creus. Additional financial support was provided by project Ref. CTM2009-08602 and a Ramo´n y Cajal Research contract (J. Lloret) from the Spanish Ministry of Science & Innovation

Shark reactions to scuba divers in two marine protected areas of the Eastern Tropical Pacific

Abstract: 1. Worldwide, there are concerns about the potential impact of a growing tourism industry on the behaviour and ecology of sharks. Several shark species are key attractions in the scuba diving industry in both the Galapagos Marine Reserve (Ecuador) and the Sanctuary of Fauna and Flora Malpelo (Colombia). 2. In this study, the reactions of five species of shark to the behaviour of scuba divers were investigated in the Galapagos and Malpelo. 3. Four discrete categories of shark reaction (evasion, spontaneous approach, alert and no reaction) were identified and analysed against five categories of diver behaviour (direct approach, camera flash, sudden movement, noise and simple presence), two categories of observation strategy (still and movement) and the distance of the focal diver group to the sharks. 4. The type of reaction in the sharks was determined by the behaviour of the divers, their distance to the fish and, especially, by their observation strategy. Shark reactions varied between species and locations and divers acted more intrusively towards those species they were not afraid of, and which they could access more easily due to the conditions of their environment. 5. ‘Direct approach’, ‘sudden movement’, the observation strategy ‘moving’ and distances closer than 4 m between divers and sharks elicited stronger behavioural responses by the species targeted. Recommendations are given for the preferred actions divers should employ in order to diminish the effects on the target species analysed in this study. Copyright © 2011 John Wiley & Sons, Ltd.

Nearshore fish assemblages associated with introduced predatory fishes in lakes

Abstract: Changes to native fish assemblages in lakes are commonly associated with introduced predatory fishes. How fish assemblages change as multiple predatory species are introduced is not well understood. This study investigated the relationship between the presence of introduced large-bodied predatory fishes (largemouth bass Micropterus salmoides, pike Esox lucius, rock bass Ambloplites rupestris, smallmouth bass Micropterus dolomieu, walleye Sander vitreus) and the composition of native fish assemblages in littoral areas of 40 lakes in Algonquin Provincial Park, Ontario, Canada. Fish assemblages were compared across lakes of different predator composition, and within lakes before and after recent predator invasions. The presence of an introduced predator was associated with significantly different native fish assemblages across lakes, after controlling for environmental and spatial variables. Native fish assemblages did not significantly vary across lakes with more than one predator species. Furthermore, while declines in native species richness over time were observed in a number of lakes, these were not associated with introductions of additional predators. Several small-bodied species (brook stickleback Culea inconstans, fathead minnow Pimephales promelas, finescale dace Chrosomus neogaeus, and northern redbelly dace Chrosomus eos) consistently showed strong negative correlations with predator presence. The results suggest that predatory fish introductions alter native fish assemblages and that this impact is consistent regardless of the number of predatory species introduced. Copyright © 2011 John Wiley & Sons, Ltd and Her Majesty the Queen in Right of Canada.

Population structure of the migratory fish Prochilodus lineatus (Characiformes) from rio Grande basin (Brazil), an area fragmented by dams

Abstract: 1. Prochilodus lineatus (Prochilodontidae, Characiformes) is a migratory species of great economic importance both in fisheries and aquaculture that is found throughout the Jacui, Paraiba do Sul, Parana, Paraguay and Uruguay river basins in South America. Earlier population studies of P. lineatus in the rio Grande basin (Parana basin) indicated the existence of a single population; however, the range of this species has been fragmented by the construction of several dams. Such dams modified the environmental conditions and could have constrained the reproductive migration of P. lineatus, possibly leading to changes in the population genetic structure. 2. In order to evaluate how genetic diversity is allocated in the rio Grande basin, 141 specimens of P. lineatus from eight collection sites were analysed using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) with 15 restriction enzymes. 3. Forty-six haplotypes were detected, and 70% of them are restricted. The mean genetic variability indexes (h = 0.7721 and π = 1.6%) were similar to those found in natural populations with a large effective size. Fst and Exact Test values indicated a lack of structuring among the samples, and the model of isolation by distance was tested and rejected. 4. The haplotype network indicated that this population of P. lineatus has been maintained as a single variable stock with some differences in the genetic composition (haplotypes) between samples. Indications of population expansion were detected, and this finding was supported by neutrality tests and mismatch distribution analyses. 5. The present study focused on regions between dams to serve as a parameter for further evaluations of genetic variability and the putative impact of dams and repopulation programmes in natural populations of P. lineatus. Copyright © 2011 John Wiley & Sons, Ltd.

Explaining spatial variability in stream habitats using both natural and management‐influenced landscape predictors

Abstract: The distribution and composition of in-stream habitats are reflections of landscape scale geomorphic and climatic controls. Correspondingly, Pacific salmon (Oncorhynchus spp.) are largely adapted to and constrained by the quality and complexity of those in-stream habitat conditions. The degree to which lands have been fragmented and managed can disrupt these patterns and affect overall habitat availability and quality. Eleven in-stream habitat features were modelled as a function of landscape composition. In total, 121 stream reaches within coastal catchments of Oregon were modelled. For each habitat feature, three linear regression models were applied in sequence; final models were composed of the immutable and management-influenced landscape predictors that best described the variability in stream habitat. Immutable landscape predictors considered proxies for stream power described the majority of the variability seen in stream habitat features. Management-influenced landscape predictors, describing the additional human impacts beyond that which was inherently entwined with the immutable predictors, explained a sizeable proportion of variability. The largest response was seen in wood volume and pool frequency. By using a sequential linear regression analysis, management-influenced factors could be segregated from natural gradients to identify those stream habitat features that may be more sensitive to land-use pressures. These results contribute to the progressing notion that the conservation of freshwater resources is best accomplished by investigating and managing stream systems from a landscape perspective. Copyright © 2011 John Wiley & Sons, Ltd.

Rediscovery of the largest population of the freshwater pearl mussel (Margaritifera margaritifera) in the Leningrad oblast (north‐west Russia)

Abstract: 1. An internationally important population of the freshwater pearl mussel (Margaritifera margaritifera) was rediscovered in a small river in north-west Russia. 2. A survey of visible mussels in 2008/2009 indicated an estimated population of 40 000 individuals. This is the largest population currently known in the Leningrad oblast and is comparable with the entire pearl mussel population of some western European countries. 3. The average density of visible mussels was 29.6 individuals m−2 in the middle part of the river. In the four largest mussel beds maximum densities of 1000+ individuals m−2 were recorded. Such densities are exceptional and have not been reported elsewhere in Europe during the last 100 years. 4. Live juvenile mussels were recorded, indicating that that this population is viable, although further investigation is required to establish its status. 5. Analysis of the population age structure, based on the measurement of empty shells, showed an age class distribution similar to those reported for other healthy Margaritifera populations. 6. Only two live juveniles were found. However, this is likely to be due to the survey being restricted to counts of visible mussels only, and the age structure being based on the analysis of dead shells. 7. The population's current status and possible reasons for its survival in this river are discussed. Conservation measures should include the construction of a fish ladder to make fish migration through the culvert possible, removal of a metal screen preventing fish migration from the upper reaches of the river to the lake, reduction of recreation activities, and providing the local children's camp with water treatment facilities. Copyright © 2011 John Wiley & Sons, Ltd.

Reference vs. present-day condition: early planning decisions influence the achievement of conservation objectives

Abstract: 1. A vast scientific literature has been devoted to identifying the best way to represent biodiversity for conservation in the last decade. Methods exist for deciding how to use scarce information and avoid omission and commission errors. The effect of these errors on reserve efficiency does not arise only from the accuracy of data representing conservation features, as usually considered. There are also several underlying assumptions associated with the type of data used that might affect accuracy of conservation decision-making and compromise achievement of conservation objectives. 2. Here the effects of two management scenarios on selection of priority areas for conservation are explored. The spatial distribution of 10 native freshwater fish species in an Iberian basin under present-day and reference conditions were modelled and priority areas for both scenarios using the same spatial and cost constraints were identified. 3. Priority areas identified under the present-day scenario reflected the up-to-date spatial distribution of species and avoided the selection of highly perturbed and costly areas. The isolated spatial distribution of native populations imposed by the current perturbation status limited the spatial connectivity between priority areas under the present-day scenario. Most importantly for the achievement of conservation objectives, priority areas selected under both scenarios did not overlap. 4. Given that the reference scenario was based on potential presence of native species the actual representation of species would be overestimated if consideration were not given to restoring reference conditions (high commission errors). Based on results obtained it is recommended that planners give more consideration to the current perturbation status when identifying priority areas for conservation.