Showing papers in "Advances in Marine Biology in 2014"

Environmental Effects on Cephalopod Population Dynamics: Implications for Management of Fisheries

Abstract: Cephalopods are a relatively small class of molluscs (~ 800 species), but they support some large industrial scale fisheries and numerous small-scale, local, artisanal fisheries. For several decades, landings of cephalopods globally have grown against a background of total finfish landings levelling off and then declining. There is now evidence that in recent years, growth in cephalopod landings has declined. The commercially exploited cephalopod species are fast-growing, short-lived ecological opportunists. Annual variability in abundance is strongly influenced by environmental variability, but the underlying causes of the links between environment and population dynamics are poorly understood. Stock assessment models have recently been developed that incorporate environmental processes that drive variability in recruitment, distribution and migration patterns. These models can be expected to improve as more, and better, data are obtained on environmental effects and as techniques for stock identification improve. A key element of future progress will be improved understanding of trophic dynamics at all phases in the cephalopod life cycle. In the meantime, there is no routine stock assessment in many targeted fisheries or in the numerous by-catch fisheries for cephalopods. There is a particular need for a precautionary approach in these cases. Assessment in many fisheries is complicated because cephalopods are ecological opportunists and stocks appear to have benefited from the reduction of key predator by overexploitation. Because of the complexities involved, ecosystem-based fisheries management integrating social, economic and ecological considerations is desirable for cephalopod fisheries. An ecological approach to management is routine in many fisheries, but to be effective, good scientific understanding of the relationships between the environment, trophic dynamics and population dynamics is essential. Fisheries and the ecosystems they depend on can only be managed by regulating the activities of the fishing industry, and this requires understanding the dynamics of the stocks they exploit.

Cephalopod culture: current status of main biological models and research priorities.

Abstract: A recent revival in using cephalopods as experimental animals has rekindled interest in their biology and life cycles, information with direct applications also in the rapidly growing ornamental aquarium species trade and in commercial aquaculture production for human consumption. Cephalopods have high rates of growth and food conversion, which for aquaculture translates into short culture cycles, high ratios of production to biomass and high cost-effectiveness. However, at present, only small-scale culture is possible and only for a few species: the cuttlefish Sepia officinalis , the loliginid squid Sepioteuthis lessoniana and the octopuses Octopus maya and O. vulgaris . These four species are the focus of this chapter, the aims of which are as follows: (1) to provide an overview of the culture requirements of cephalopods, (2) to highlight the physical and nutritional requirements at each phase of the life cycle regarded as essential for successful full-scale culture and (3) to identify current limitations and the topics on which further research is required. Knowledge of cephalopod culture methods is advanced, but commercialization is still constrained by the highly selective feeding habits of cephalopods and their requirement for large quantities of high-quality (preferably live) feed, particularly in the early stages of development. Future research should focus on problems related to the consistent production of viable numbers of juveniles, the resolution of which requires a better understanding of nutrition at all phases of the life cycle and better broodstock management, particularly regarding developments in genetic selection, control of reproduction and quality of eggs and offspring.

The study of deep-sea cephalopods.

Abstract: "Deep-sea" cephalopods are here defined as cephalopods that spend a significant part of their life cycles outside the euphotic zone. In this chapter, the state of knowledge in several aspects of deep-sea cephalopod research are summarized, including information sources for these animals, diversity and general biogeography and life cycles, including reproduction. Recommendations are made for addressing some of the remaining knowledge deficiencies using a variety of traditional and more recently developed methods. The types of oceanic gear that are suitable for collecting cephalopod specimens and images are reviewed. Many groups of deep-sea cephalopods require taxonomic reviews, ideally based on both morphological and molecular characters. Museum collections play a vital role in these revisions, and novel (molecular) techniques may facilitate new use of old museum specimens. Fundamental life-cycle parameters remain unknown for many species; techniques developed for neritic species that could potentially be applied to deep-sea cephalopods are discussed. Reproductive tactics and strategies in deep-sea cephalopods are very diverse and call for comparative evolutionary and experimental studies, but even in the twenty-first century, mature individuals are still unknown for many species. New insights into diet and trophic position have begun to reveal a more diverse range of feeding strategies than the typically voracious predatory lifestyle known for many cephalopods. Regular standardized deep-sea cephalopod surveys are necessary to provide insight into temporal changes in oceanic cephalopod populations and to forecast, verify and monitor the impacts of global marine changes and human impacts on these populations.

The South Georgia and the South Sandwich Islands MPA: protecting a biodiverse oceanic island chain situated in the flow of the antarctic circumpolar current.

Abstract: South Georgia and the South Sandwich Islands (SGSSI) are surrounded by oceans that are species-rich, have high levels of biodiversity, important endemism and which also support large aggregations of charismatic upper trophic level species. Spatial management around these islands is complex, particularly in the context of commercial fisheries that exploit some of these living resources. Furthermore, management is especially complicated as local productivity relies fundamentally upon biological production transported from outside the area. The MPA uses practical management boundaries, allowing access for the current legal fisheries for Patagonian toothfish, mackerel icefish and Antarctic krill. Management measures developed as part of the planning process designated the whole SGSSI Maritime Zone as an IUCN Category VI reserve, within which a number of IUCN Category I reserves were identified. Multiple-use zones and temporal closures were also designated. A key multiple-use principle was to identify whether the ecological impacts of a particular fishery threatened either the pelagic or benthic domain.

Transitions during cephalopod life history: the role of habitat, environment, functional morphology and behaviour

Abstract: Cephalopod life cycles generally share a set of stages that take place in different habitats and are adapted to specific, though variable, environmental conditions. Throughout the lifespan, individuals undertake a series of brief transitions from one stage to the next. Four transitions were identified: fertilisation of eggs to their release from the female (1), from eggs to paralarvae (2), from paralarvae to subadults (3) and from subadults to adults (4). An analysis of each transition identified that the changes can be radical (i.e. involving a range of morphological, physiological and behavioural phenomena and shifts in habitats) and critical (i.e. depending on environmental conditions essential for cohort survival). This analysis underlines that transitions from eggs to paralarvae (2) and from paralarvae to subadults (3) present major risk of mortality, while changes in the other transitions can have evolutionary significance. This synthesis suggests that more accurate evaluation of the sensitivity of cephalopod populations to environmental variation could be achieved by taking into account the ontogeny of the organisms. The comparison of most described species advocates for studies linking development and ecology in this particular group.

Marine protected area networks in California, USA.

Abstract: California responded to concerns about overfishing in the 1990s by implementing a network of marine protected areas (MPAs) through two science-based decision-making processes. The first process focused on the Channel Islands, and the second addressed California's entire coastline, pursuant to the state's Marine Life Protection Act (MLPA). We review the interaction between science and policy in both processes, and lessons learned. For the Channel Islands, scientists controversially recommended setting aside 30-50% of coastline to protect marine ecosystems. For the MLPA, MPAs were intended to be ecologically connected in a network, so design guidelines included minimum size and maximum spacing of MPAs (based roughly on fish movement rates), an approach that also implicitly specified a minimum fraction of the coastline to be protected. As MPA science developed during the California processes, spatial population models were constructed to quantify how MPAs were affected by adult fish movement and larval dispersal, i.e., how population persistence within MPA networks depended on fishing outside the MPAs, and how fishery yields could either increase or decrease with MPA implementation, depending on fishery management. These newer quantitative methods added to, but did not supplant, the initial rule-of-thumb guidelines. In the future, similar spatial population models will allow more comprehensive evaluation of the integrated effects of MPAs and conventional fisheries management. By 2011, California had implemented 132 MPAs covering more than 15% of its coastline, and now stands on the threshold of the most challenging step in this effort: monitoring and adaptive management to ensure ecosystem sustainability.

Establishment, management, and maintenance of the phoenix islands protected area.

Abstract: The Republic of Kiribati's Phoenix Islands Protected Area (PIPA), located in the equatorial central Pacific, is the largest and deepest UNESCO World Heritage site on earth. Created in 2008, it was the first Marine Protected Area (MPA) of its kind (at the time of inception, the largest in the world) and includes eight low-lying islands, shallow coral reefs, submerged shallow and deep seamounts and extensive open-ocean and ocean floor habitat. Due to their isolation, the shallow reef habitats have been protected de facto from severe exploitation, though the surrounding waters have been continually fished for large pelagics and whales over many decades. PIPA was created under a partnership between the Government of Kiribati and the international non-governmental organizations-Conservation International and the New England Aquarium. PIPA has a unique conservation strategy as the first marine MPA to use a conservation contract mechanism with a corresponding Conservation Trust established to be both a sustainable financing mechanism and a check-and-balance to the oversight and maintenance of the MPA. As PIPA moves forward with its management objectives, it is well positioned to be a global model for large MPA design and implementation in similar contexts. The islands and shallow reefs have already shown benefits from protection, though the pending full closure of PIPA (and assessments thereof) will be critical for determining success of the MPA as a refuge for open-ocean pelagic and deep-sea marine life. As global ocean resources are continually being extracted to support a growing global population, PIPA's closure is both timely and of global significance.

Understanding the scale of Marine protection in Hawai'i: from community-based management to the remote Northwestern Hawaiian Islands.

Abstract: Ancient Hawaiians developed a sophisticated natural resource management system that included various forms of spatial management. Today there exists in Hawai‘i a variety of spatial marine management strategies along a range of scales, with varying degrees of effectiveness. State-managed no-take areas make up less than 0.4% of nearshore waters, resulting in limited ecological and social benefits. There is increasing interest among communities and coastal stakeholders in integrating aspects of customary Hawaiian knowledge into contemporary co-management. A network of no-take reserves for aquarium fish on Hawai‘i Island is a stakeholder-driven, adaptive management strategy that has been successful in achieving ecological objectives and economic benefits. A network of large-scale no-take areas for deepwater (100–400 m) bottomfishes suffered from a lack of adequate data during their initiation; however, better technology, more ecological data, and stakeholder input have resulted in improvements and the ecological benefits are becoming clear. Finally, the Papahānaumokuākea Marine National Monument (PMNM) is currently the single largest conservation area in the United States, and one of the largest in the world. It is considered an unqualified success and is managed under a new model of collaborative governance. These case studies allow an examination of the effects of scale on spatial marine management in Hawai‘i and beyond that illustrate the advantages and shortcomings of different management strategies. Ultimately a marine spatial planning framework should be applied that incorporates existing marine managed areas to create a holistic, regional, multi-use zoning plan engaging stakeholders at all levels in order to maximize resilience of ecosystems and communities.

Spatial management of fisheries in the mediterranean sea: problematic issues and a few success stories.

Abstract: Fishing has been important in the Mediterranean region for many centuries and still has a central role in its economic importance and cultural heritage. A multitude of fishery-oriented marine managed areas have been implemented under a highly complex political and legislative framework to protect fishery resources and sensitive habitats from high impact uses. However, a review of the literature revealed that few data are available to support their effectiveness, except for a few studies on fishery reserves and marine reserves. In these cases, fish biomass has increased and some evidence of ecological and socioeconomic benefits has been documented. The environmental and geopolitical complexity of the Mediterranean region as well as the dominant top-down management approaches, constitute the weakest points in the spatial management of fisheries at regional level. A coordinating role of all national and supranational bodies present in the area is desirable in the near future.

The creation of the Chagos marine protected area: a fisheries perspective(☆).

Abstract: From a fisheries perspective, the declaration of a 640,000 km² "no-take" Marine Protected Area (MPA) in the Chagos Archipelago in 2010 was preceded by inadequate consideration of the scientific rationale for protection. The entire area was already a highly regulated zone which had been subject to a well-managed fisheries licensing system. The island of Diego Garcia, the only area where there is evidence of overfishing has, because of its military base, been excluded from the MPA. The no-take mandate removes the primary source of sustenance and economic sustainability of any inhabitants, thus effectively preventing the return of the original residents who were removed for political reasons in the 1960s and 1970s. The principles of natural resource conservation and use have been further distorted by forcing offshore fishing effort to other less well-managed areas where it will have a greater negative impact on the well-being of the species that were claimed to be one of the primary beneficiaries of the declaration. A failure to engage stakeholders has resulted in challenges in both the English courts and before an international tribunal.

Diverging strategies to planning an ecologically coherent network of MPAs in the North Sea: the roles of advocacy, evidence and pragmatism in the face of uncertainty.

Abstract: The North Sea is one of the most economically important seas in the world due to productive fisheries, extensive oil and gas fields, busy shipping routes, marine renewable energy development and recreational activity. Unsurprisingly, therefore, the use of marine protected areas (here defined widely to include fisheries closed areas and no-take marine reserves) in its management has generated considerable controversy-particularly with regards to the design of a regional ecologically coherent MPA network to meet international obligations. Drawing on three MPA processes currently occurring in the UK North Sea, we examine the real-world problems that make the designation of MPA networks challenging. The political problems include: disagreement among (and within) sectors over policy objectives and priorities, common access to fisheries resources at the EU level increasing the scale at which decisions have to be made and lack of an integrated strategy for implementing protected areas in the North Sea. The scientific problems include the patchy knowledge of benthic assemblages, limited knowledge of fishing gear-habitat interactions, and the increased risk of unforeseen externalities if human activity (predominantly fishing) is displaced from newly protected sites. Diverging stakeholder attitudes to these problems means that there is no consensus on what ecological coherence actually means. Ultimately, we caution against 'quick-fix' solutions that are based on advocacy and targets, as they create confusion and undermine trust in the planning process. We argue for a more pragmatic approach to marine protection that embraces the complexity of the social and political arena in which decisions are made.

Ecology of artificial reefs in the subtropics.

Abstract: The application of artificial reefs (ARs) has a long history, and there is a wealth of information related to the design and performance of ARs in coastal and ocean waters worldwide. However, relatively fewer studies in the literature are focused on the response of benthic communities within the reef areas than those on fish attraction and fish production and on the settlement and colonization of epibiota on the AR structures, especially in the subtropics where seasonal differences and environmental conditions can be large. Recent advances in the understanding of the ecology of ARs in the subtropics are highlighted, with a focus on fish attraction versus fish production, development of epibiota on AR systems and responses of in situ benthic communities in the reef areas. Data are also presented on studies of trophic relationships in subtropical AR systems, and further research areas using analyses of biological traits, stable isotope signatures and fatty acid profiles in investigating the ecology of ARs are proposed.

Inadequate evaluation and management of threats in Australia's Marine Parks, including the Great Barrier Reef, misdirect Marine conservation.

Abstract: The magnificence of the Great Barrier Reef and its worthiness of extraordinary efforts to protect it from whatever threats may arise are unquestioned. Yet almost four decades after the establishment of the Great Barrier Reef Marine Park, Australia's most expensive and intensely researched Marine Protected Area, the health of the Reef is reported to be declining alarmingly. The management of the suite of threats to the health of the reef has clearly been inadequate, even though there have been several notable successes. It is argued that the failure to prioritise correctly all major threats to the reef, coupled with the exaggeration of the benefits of calling the park a protected area and zoning subsets of areas as 'no-take', has distracted attention from adequately addressing the real causes of impact. Australia's marine conservation efforts have been dominated by commitment to a National Representative System of Marine Protected Areas. In so doing, Australia has displaced the internationally accepted primary priority for pursuing effective protection of marine environments with inadequately critical adherence to the principle of having more and bigger marine parks. The continuing decline in the health of the Great Barrier Reef and other Australian coastal areas confirms the limitations of current area management for combating threats to marine ecosystems. There is great need for more critical evaluation of how marine environments can be protected effectively and managed efficiently.

Introduction to marine managed areas.

Abstract: No issue in marine conservation and management seems to have generated as much interest, and controversy as marine protected areas (MPAs). In the past 30 years, a substantial scientific literature on the subject has developed, international agreements have set targets for proportion of the sea to be protected, and hundreds of millions of dollars have been spent on research and advocacy for MPA establishment. While the objectives of MPAs are diverse, few studies evaluate the success of MPAs against stated objectives. It is clear that well-enforced MPAs will protect enough fish from exploitation that within reserves abundance increases, fish live to be larger, and measures of diversity are higher. What is much more poorly understood is the impacts of reserve establishment on areas outside reserves. Theory suggests that when stocks are seriously overfished outside reserves, the yield and abundance outside the reserves may be increased by spillover from the reserve. When stocks are not overexploited, reserve establishment will likely decrease the total yield. The chapters in this volume explore a broad set of case studies of MPAs, their objectives and their outcomes.

Reproductive biology of female Norway lobster, Nephrops norvegicus (Linnaeus, 1758) Leach, in Icelandic waters during the period 1960-2010: comparative overview of distribution areas in the Northeast Atlantic and the Mediterranean.

Abstract: Maturity size, reproductive cycle, sex ratio and fecundity of female Nephrops were investigated at SW, S and SE Iceland for the period 1960-2010. Time series of biological parameters and fisheries data displayed significant relationships. In addition, female biological data from 20 areas in the Atlantic and Mediterranean were compared. Fifty percentage maturity estimates had an overall range of 23.9-34.4mm CL with some anomalies in the 2000s. The reproductive cycle in Iceland has been biennial during the whole study period from mid-1960s to 2010 with minor change in phase in the 2000s. Biennial moulting retards female growth more than annual spawning, and the length of incubation and hatch time of year show significant relationships with latitude and sea temperature. Variations in sex ratio were observed and relationships found between female sex ratio and CL, CPUE and stock biomass during 1961-2010, displaying apparent fishery-induced effects on sex ratio. Potential and realized fecundity estimates in Iceland are 35-50% of those reported from more southerly waters. Biennial spawning and low fecundity limit the number of progeny in Icelandic Nephrops and necessitate lower fishing mortality. Ambient temperature in Icelandic waters has risen by 1°C since the late 1990s, generating around 30 days shorter incubation time in the 2000s, but around 3°C rise is necessary for possible annual spawning.

Marine managed areas and associated fisheries in the US Caribbean.

Abstract: The marine managed areas (MMAs) of the U.S. Caribbean are summarized and specific data-rich cases are examined to determine their impact upon fisheries management in the region. In this region, the productivity and connectivity of benthic habitats such as mangroves, seagrass and coral reefs is essential for many species targeted by fisheries. A minority of the 39 MMAs covering over 4000 km 2 serve any detectable management or conservation function due to deficiencies in the design, objectives, compliance or enforcement. Fifty percent of the area within MMA boundaries had no-take regulations in the U.S. Virgin Islands, while Puerto Rico only had 3%. Six case studies are compared and contrasted to better understand the potential of these MMAs for fisheries management. Signs of success were associated with including sufficient areas of essential fish habitat (nursery, spawning and migration corridors), year-round no-take regulations, enforcement and isolation. These criteria have been identified as important in the conservation of marine resources, but little has been done to modify the way MMAs are designated and implemented in the region. Site-specific monitoring to measure the effects of these MMAs is needed to demonstrate the benefits to fisheries and gain local support for a greater use as a fisheries management tool.