Fishing groupers towards extinction: a global assessment of threats and extinction risks in a billion dollar fishery
University of Hong Kong1, University of Puerto Rico at Mayagüez2, Old Dominion University3, Norwich University4, Centre for Environment, Fisheries and Aquaculture Science5, James Cook University6, Federal University of Pernambuco7, South African Institute for Aquatic Biodiversity8, Xiamen University9, Australian Museum10, University of Hawaii at Hilo11, California Academy of Sciences12
TL;DR: Given that the major threat is overfishing, accompanied by a general absence and/or poor application of fishery management, the prognosis for restoration and successful conservation of Threatened species is poor.
Abstract: Groupers are a valuable fishery resource of reef ecosystems and are among those species most vulnerable to fishing pressure because of life history characteristics including longevity, late sexual maturation and aggregation spawning. Despite their economic importance, few grouper fisheries are regularly monitored or managed at the species level, and many are reported to be undergoing declines. To identify major threats to groupers, the International Union for Conservation of Nature (IUCN) Red List criteria were applied to all 163 species. Red List assessments show that 20 species (12%) risk extinction if current trends continue, and an additional 22 species (13%) are considered to be Near Threatened. The Caribbean Sea, coastal Brazil and Southeast Asia contain a disproportionate number of Threatened species, while numerous poorly documented and Near Threatened species occur in many regions. In all, 30% of all species are considered to be Data Deficient. Given that the major threat is overfishing, accompanied by a general absence and/or poor application of fishery management, the prognosis for restoration and successful conservation of Threatened species is poor. We believe that few refuges remain for recovery and that key biological processes (e.g. spawning aggregations) continue to be compromised by uncontrolled fishing. Mariculture, through hatchery-rearing, increases production of a few species and contributes to satisfying high market demand, but many such operations depend heavily on wild-caught juveniles with resultant growth and recruitment overfishing. Better management of fishing and other conservation efforts are urgently needed, and we provide examples of possible actions and constraints.
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TL;DR: The figures suggest that the conservation status of South American freshwater fish faunas is better than in most other regions of the world, but the marine fishes are as threatened as elsewhere.
Abstract: The freshwater and marine fish faunas of South America are the most diverse on Earth, with current species richness estimates standing above 9100 species. In addition, over the last decade at least 100 species were described every year. There are currently about 5160 freshwater fish species, and the estimate for the freshwater fish fauna alone points to a final diversity between 8000 and 9000 species. South America also has c. 4000 species of marine fishes. The mega-diverse fish faunas of South America evolved over a period of >100 million years, with most lineages tracing origins to Gondwana and the adjacent Tethys Sea. This high diversity was in part maintained by escaping the mass extinctions and biotic turnovers associated with Cenozoic climate cooling, the formation of boreal and temperate zones at high latitudes and aridification in many places at equatorial latitudes. The fresh waters of the continent are divided into 13 basin complexes, large basins consolidated as a single unit plus historically connected adjacent coastal drainages, and smaller coastal basins grouped together on the basis of biogeographic criteria. Species diversity, endemism, noteworthy groups and state of knowledge of each basin complex are described. Marine habitats around South America, both coastal and oceanic, are also described in terms of fish diversity, endemism and state of knowledge. Because of extensive land use changes, hydroelectric damming, water divergence for irrigation, urbanization, sedimentation and overfishing 4-10% of all fish species in South America face some degree of extinction risk, mainly due to habitat loss and degradation. These figures suggest that the conservation status of South American freshwater fish faunas is better than in most other regions of the world, but the marine fishes are as threatened as elsewhere. Conserving the remarkable aquatic habitats and fishes of South America is a growing challenge in face of the rapid anthropogenic changes of the 21st century, and deserves attention from conservationists and policy makers.
432 citations
TL;DR: In this paper, the authors evaluate the interaction between spawning aggregations and fishing activities, and test for hyperstability in fishery-dependent and fishery independent data sets to assess stock trends in the barred sand bass (Paralabrax nebulifer) and the kelp bass (paral- abrax clathratus).
Abstract: Fisheries that target fish spawning aggregations can exhibit hyperstability, in which catch per unit effort (CPUE) remains elevated as stock abundance declines, but empirical support is limited. We compiled several fishery-dependent and fishery-independent data sets to assess stock trends in the barred sand bass (Paralabrax nebulifer) and the kelp bass (Paral- abrax clathratus) in southern California, USA, evaluate the interaction between spawning aggregations and fishing activities, and test for hyperstability. Annual and seasonal trends from fisheries and population data indicate that regional stocks of both species have collapsed in response to overfishing of spawning aggregations and changes in environmental conditions. The aggregating behavior of fish and persistent targeting of spawning aggregations by recreational fisheries combined to produce a hyperstable relationship between CPUE and stock abundance in both species, which created the illusion that pop- ulation levels were stable and masked fishery collapses. Differences in the rate of decline between the two species may be related to the size, duration, and spatial distribution of their spawning aggregations. Results of this study provide empirical evidence of hyperstability in aggregation-based fisheries and demonstrate that CPUE data be used with caution and given low weight when fishery-independent data are available.
233 citations
California Academy of Sciences1, Museu Paraense Emílio Goeldi2, Australian Museum3, Smithsonian Institution4, Natural History Museum5, Field Museum of Natural History6, Villanova University7, University of Milano-Bicocca8, Utica College9, King Abdullah University of Science and Technology10, University of Costa Rica11, University of California, Berkeley12, University of Kansas13, University of Los Andes14, Old Dominion University15, Louisiana State University16, James Cook University17, University of Auckland18, National Oceanic and Atmospheric Administration19, University of Chicago20, American Museum of Natural History21, University of São Paulo22, Federal University of Rio de Janeiro23, University of California, Davis24, Conservation International25, University of Nevada, Reno26, Addis Ababa University27, University of Sydney28, Museum Victoria29, University of Colorado Boulder30, Harvard University31, National University of Singapore32, Smithsonian Tropical Research Institute33, Cornell University34, Marien Ngouabi University35, University of Wisconsin–Parkside36, Cincinnati Museum Center37, Australian National University38, University of Michigan39, California State University, Fullerton40, University of Florida41, Central University of Venezuela42, Pontifical Catholic University of Chile43, University of New Mexico44, CSIRO Marine and Atmospheric Research45, Bishop Museum46, University of the Ryukyus47, Museum für Naturkunde48, Naturhistorisches Museum49, Long Island University50, Auckland War Memorial Museum51, Royal Belgian Institute of Natural Sciences52, McGill University53, University of Alaska Fairbanks54, Royal Ontario Museum55
TL;DR: Collecting biological specimens for scientific studies came under scrutiny when B. A. Minteer and colleagues suggested that this practice plays a significant role in species extinctions.
Abstract: Collecting biological specimens for scientific studies came under scrutiny when B. A. Minteer et al. [“Avoiding (re)extinction,” Perspectives, 18 April, p. [260][1]] suggested that this practice plays a significant role in species extinctions. Based on a small number of examples (rare birds,
181 citations
TL;DR: Sawfish are among the world's largest marine fishes, and they are caught by a wide range of fishing gears owing to their tooth-studded rostra being easily entangled, and their rostra have long been traded as curios.
Abstract: Sawfish are arguably the world's most imperilled marine fishes. All five species are classified as highly threatened with extinction: three are Critically Endangered (smalltooth sawfish Pristis pectinata, largetooth sawfish Pristis pristis, and green sawfish Pristis zijsron); two are Endangered (narrow sawfish Anoxypristis cuspidata, and dwarf sawfish Pristis clavata).
Sawfishes are threatened primarily due to a combination of their low intrinsic rates of population increase, high catchability in fisheries, and high value. Sawfishes are among the world's largest marine fishes, and they are caught by a wide range of fishing gears owing to their tooth-studded rostra being easily entangled. Sawfish fins are some of the most valuable for shark fin soup, and their rostra have long been traded as curios. In addition, they inhabit shallow coastal waters, estuaries, and rivers of the tropics and subtropics, down to a maximum depth rarely exceeding 100 m and are associated with threatened mangrove and seagrass habitats.
Historically, sawfishes were distributed in the coastal waters of 90 countries and territories. Over the past century, their geographic distribution has been greatly diminished. For example, the smalltooth sawfish is now found in <20% of its former range. Globally, sawfishes are now entirely absent from 20 countries; 43 countries have lost at least one species.
Sawfishes are legally protected, to some degree, in 16 of the 90 range states. These safeguards encompass, on average, 81% of their Extant distribution; however, the quality and breadth of protection varies dramatically across countries and species. Smalltooth sawfish currently has the least amount of such coverage of only half (49%) of Extant distribution.
The global conservation strategy specifies actions to protect sawfish and their habitats. Such actions are urgently warranted to avoid global extinction and to restore robust populations for the benefit of coastal ecosystem function and biodiversity.
© 2014 The Authors. Aquatic Conservation: Marine and Freshwater Ecosystems published by John Wiley & Sons, Ltd.
139 citations
TL;DR: In this article, the authors provide a series of evidenced-based arguments that support an urgent need to recognize fish spawning aggregations as a focal point for fisheries management and conservation on a global scale, with a particular emphasis placed on the protection of multispecies FSA sites.
Abstract: Marine ecosystem management has traditionally been divided between fisheries management and biodiversity conservation approaches, and the merging of these disparate agendas has proven difficult. Here, we offer a pathway that can unite fishers, scientists, resource managers and conservationists towards a single vision for some areas of the ocean where small investments in management can offer disproportionately large benefits to fisheries and biodiversity conservation. Specifically, we provide a series of evidenced-based arguments that support an urgent need to recognize fish spawning aggregations (FSAs) as a focal point for fisheries management and conservation on a global scale, with a particular emphasis placed on the protection of multispecies FSA sites. We illustrate that these sites serve as productivity hotspots – small areas of the ocean that are dictated by the interactions between physical forces and geomorphology, attract multiple species to
134 citations
Cites background from "Fishing groupers towards extinction..."
...%) of groupers risk extinction if current fishing trends continue (Sadovy de Mitcheson et al. 2013), and a comparative analysis among grouper species of known reproductive strategy demonstrated that spawning aggregation formation is associated with higher extinction risk (Sadovy de Mitcheson and…...
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...…is now considered endangered by IUCN and being considered for listing as threatened under the US Endangered Species Act (ESA) after decades of overfishing resulted in the disappearance of the majority of FSAs throughout its geographic range (Sadovy and Eklund 1999; Sadovy de Mitcheson et al. 2013)....
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References
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TL;DR: The ecological roles of critical functional groups (for both corals and reef fishes) that are fundamental to understanding resilience and avoiding phase shifts from coral dominance to less desirable, degraded ecosystems are reviewed.
Abstract: The worldwide decline of coral reefs calls for an urgent reassessment of current management practices. Confronting large-scale crises requires a major scaling-up of management efforts based on an improved understanding of the ecological processes that underlie reef resilience. Managing for improved resilience, incorporating the role of human activity in shaping ecosystems, provides a basis for coping with uncertainty, future changes and ecological surprises. Here we review the ecological roles of critical functional groups (for both corals and reef fishes) that are fundamental to understanding resilience and avoiding phase shifts from coral dominance to less desirable, degraded ecosystems. We identify striking biogeographic differences in the species richness and composition of functional groups, which highlight the vulnerability of Caribbean reef ecosystems. These findings have profound implications for restoration of degraded reefs, management of fisheries, and the focus on marine protected areas and biodiversity hotspots as priorities for conservation.
3,032 citations
"Fishing groupers towards extinction..." refers background in this paper
...The identification of the mechanisms driving extinction risk is therefore of utmost importance to address the ‘coral reef crisis’ (Bellwood et al. 2004), especially for species or species groups of importance to fisheries that may face ‘double jeopardy’ in the face of large-scale environmental…...
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...The identification of the mechanisms driving extinction risk is therefore of utmost importance to address the ‘coral reef crisis’ (Bellwood et al. 2004), especially for species or species groups of importance to fisheries that may face ‘double jeopardy’ in the face of large-scale environmental change....
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TL;DR: The analysis suggests that management based on recent data alone may be misleading, and provides minimum estimates for unexploited communities, which could serve as the 'missing baseline' needed for future restoration efforts.
Abstract: Serious concerns have been raised about the ecological effects of industrialized fishing1, 2, 3, spurring a United Nations resolution on restoring fisheries and marine ecosystems to healthy levels4. However, a prerequisite for restoration is a general understanding of the composition and abundance of unexploited fish communities, relative to contemporary ones. We constructed trajectories of community biomass and composition of large predatory fishes in four continental shelf and nine oceanic systems, using all available data from the beginning of exploitation. Industrialized fisheries typically reduced community biomass by 80% within 15 years of exploitation. Compensatory increases in fast-growing species were observed, but often reversed within a decade. Using a meta-analytic approach, we estimate that large predatory fish biomass today is only about 10% of pre-industrial levels. We conclude that declines of large predators in coastal regions5 have extended throughout the global ocean, with potentially serious consequences for ecosystems5, 6, 7. Our analysis suggests that management based on recent data alone may be misleading, and provides minimum estimates for unexploited communities, which could serve as the ‘missing baseline’8 needed for future restoration efforts.
2,864 citations
"Fishing groupers towards extinction..." refers background in this paper
...Among harvested marine species, population declines of as much as 90% have been reported for pelagic fish species (e.g. Myers and Worm 2003), and coastal reef fishes have shown reductions of more than 4% per year since the mid-1990s in some areas (e.g. Paddack et al. 2009)....
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TL;DR: The empirical work and the theoretical literature are reviewed to assess the impacts of marine reserves on several biological measures (density, biomass, size of organisms, and diversity), paying particular attention to the role reserve size has in determining those impacts.
Abstract: Marine reserves are quickly gaining popularity as a management option for marine conservation, fisheries, and other human uses of the oceans. Despite the popularity of marine reserves as a management tool, few reserves appear to have been created or designed with an understanding of how reserves affect biological factors or how reserves can be designed to meet biological goals more effectively (e.g., attaining sustainable fish populations). This shortcoming occurs in part because the many studies that have examined the impacts of reserves on marine organisms remain isolated examples or anecdotes; the results of these many studies have not yet been synthesized. Here, I review the empirical work and discuss the theoretical literature to assess the impacts of marine reserves on several biological measures (density, biomass, size of organisms, and diversity), paying particular attention to the role reserve size has in determining those impacts. The results of 89 separate studies show that, on average, with the exception of invertebrate biomass and size, values for all four biological measures are significantly higher inside reserves compared to outside (or after reserve establishment vs. before) when evaluated for both the overall communities and by each functional group within these communities (carniv- orous fishes, herbivorous fishes, planktivorous fishes/invertebrate eaters, and invertebrates). Surprisingly, results also show that the relative impacts of reserves, such as the proportional differences in density or biomass, are independent of reserve size, suggesting that the effects of marine reserves increase directly rather than proportionally with the size of a reserve. However, equal relative differences in biological measures between small and large reserves nearly always translate into greater absolute differences for larger reserves, and so larger reserves may be necessary to meet the goals set for marine reserves. The quality of the data in the reviewed studies varied greatly. To improve data quality in the future, whenever possible, studies should take measurements before and after the creation of a reserve, replicate sampling, and include a suite of representative species. Despite the variable quality of the data, the results from this review suggest that nearly any marine habitat can benefit from the implementation of a reserve. Success of a marine reserve, however, will always be judged against the expectations for that reserve, and so we must keep in mind the goals of a reserve in its design, management, and evaluation.
1,384 citations
"Fishing groupers towards extinction..." refers background in this paper
...…MPAs in theory offer certain fishery-related benefits beyond MPA boundaries, these are not well or extensively demonstrated at the present time, and most MPAs are small relative to the typical lifetime movements of many larger reef fishes (e.g. Halpern 2003; Sale et al. 2005; Little et al. 2009)....
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Michael R. Hoffmann1, Craig Hilton-Taylor2, Ariadne Angulo2, Monika Böhm3 +170 more•Institutions (81)
TL;DR: Though the threat of extinction is increasing, overall declines would have been worse in the absence of conservation, and current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups.
Abstract: Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species.
1,333 citations
"Fishing groupers towards extinction..." refers background in this paper
...Hoffman et al. (2010) concluded that one-fifth of all vertebrates are at risk of extinction based on the IUCN criteria....
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...Hoffman et al. (2010) also demonstrated that without conservation efforts, the rate of loss would have been significantly higher....
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International Union for Conservation of Nature and Natural Resources1, Indonesian Institute of Sciences2, National Oceanic and Atmospheric Administration3, Brown University4, University of Costa Rica5, University of Hawaii at Manoa6, University of Tasmania7, Newcastle University8, Smithsonian Tropical Research Institute9, National Museum of Natural History10, De La Salle University11, University of the South Pacific12, National Marine Fisheries Service13, Silliman University14, James Cook University15, Zoological Society of London16, University of Warwick17, Conservation International18, Museum of Tropical Queensland19, University of Puerto Rico20, Marine Conservation Society21
TL;DR: The Caribbean has the largest proportion of corals in high extinction risk categories, whereas the Coral Triangle has the highest proportion of species in all categories of elevated extinction risk.
Abstract: The conservation status of 845 zooxanthellate reef-building coral species was assessed by using International Union for Conservation of Nature Red List Criteria. Of the 704 species that could be assigned conservation status, 32.8% are in categories with elevated risk of extinction. Declines in abundance are associated with bleaching and diseases driven by elevated sea surface temperatures, with extinction risk further exacerbated by local-scale anthropogenic disturbances. The proportion of corals threatened with extinction has increased dramatically in recent decades and exceeds that of most terrestrial groups. The Caribbean has the largest proportion of corals in high extinction risk categories, whereas the Coral Triangle (western Pacific) has the highest proportion of species in all categories of elevated extinction risk. Our results emphasize the widespread plight of coral reefs and the urgent need to enact conservation measures.
1,272 citations
"Fishing groupers towards extinction..." refers background in this paper
...Numerous taxa have been evaluated for extinction risk, and two recent reviews have highlighted these risks for groups that provide the foundation for marine ecosystems worldwide [e.g. corals (Carpenter et al. 2008) and seagrasses (Short et al. 2011)]....
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...corals (Carpenter et al. 2008) and seagrasses (Short et al....
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