Dwindling food-fish species and fishers' preference: problems of conserving Lake Malawi's biodiversity

Most of Malawi's popular food-fish species are in decline. The fishers attribute this decline to overfishing, changes in climate, inadequate fishing technology and supernatural powers. Sedimentation of the lake and rivers due to poor agricultural practices, which can also be implicated in the demise of Malawi's fisheries, was not recognized by the fishers. This study tested and confirmed that the fishers would readily switch to exploiting ornamental fish (Mbuna) for subsistence and cash if the more favoured food-fish species continued to dwindle. However, as most of the Mbuna species are localized to specific rocky habitats and are endemic to certain parts of the lake, they may be vulnerable to overfishing. To safeguard Lake Malawi's rich fish species diversity: (i) alternative economic opportunities for the lakeshore people should be identified, evaluated and promoted to alleviate the fishing pressure, (ii) the Department of Fisheries should collaborate with local fishermen in promoting sustainable fish utilization, e.g., through public campaigns aimed at sensitizing fishermen on the status of the fisheries and the vulnerability of some fish communities to overfishing and environmental degradation, and (iii) the degree of Mbuna exploitation, now that the popular food fishes are in decline, should be monitored and, where necessary, regulated to promote sustainability.     

Trying to collapse a population for conservation: commercial trade of a marine invasive species by artisanal fishers

Implementing new and effective control strategies to reduce populations of invasive species is needed to offset their negative impacts worldwide. The spread of Indo-Pacific lionfish (Pterois sp.) through much of the western Atlantic has been one of the most publicized marine invasions globally, and is considered a major biodiversity threat whose longer-term impacts are still uncertain. Marine managers have explored several strategies to control lionfish, such as fishing tournaments (derbies) and commercial fisheries. Commercial fisheries for invasive species are controversial because they could create perverse incentives to maintain these populations, and they have never been demonstrated to successfully control target populations. We analyzed the development and impacts of an opportunistic fishing operation aimed at commercializing invasive lionfish in the Mexican Caribbean. We examined official lionfish landings and compared them to catches from lionfish derbies and lionfish densities from locations in the state of Quintana Roo, Mexico. We found that commercial fishers, particularly from one fishing cooperative on Cozumel Island, were effective at catching lionfish, with landings peaking at 20,000 individuals in 2014. This number is comparable to the number of lionfish caught in derbies across the entire Caribbean in the same year. Ecological survey data suggest a?~?60% reduction in lionfish density on Cozumel reefs over two years (2013–2015), matching the peak landings in the lionfish fishing operation. However, the fishery’s apparent success as a control tool during the time window analyzed seemed to trigger its own demise: a decline in landings was followed by evaporating market interest and loss of economic viability. If fisheries are to be established and used as management strategies to control future invasions, managers must develop strategic collaboration plans with commercial fishing partners.

     

Overexploiting marine ecosystem engineers: potential consequences for biodiversity

Overfishing is a major environmental problem in the oceans. In addition to the direct loss of the exploited species, the very act of fishing, particularly with mobile bottom gear, destroys habitat and ultimately results in the loss of biodiversity. Furthermore, overfishing can create trophic cascades in marine communities that cause similar declines in species richness. These effects are compounded by indirect effects on habitat that occur through removal of ecological or ecosystem engineers. Mass removal of species that restructure the architecture of habitat and thus increase its complexity or influence the biogeochemistry of sediments could have devastating effects on local biodiversity and important water–sediment processes. The possible overexploitation of engineering species requires more attention because the consequences extend beyond their own decline to affect the rest of the ecosystem. This is particularly problematic in the deep ocean, where oil and gas exploration and fishing pressure are likely to increase.     

Over-exploitation of a broadcast spawning marine invertebrate: Decline of the white abalone

Marine invertebrates have long been consideredto be resistant to overfishing. However, agrowing number of exploited taxa have declinedsubstantially and even disappeared from partsof their former range. We consider the case ofthe white abalone (Haliotis sorenseni);the first marine invertebrate proposed for theUS endangered species list. This high-valuespecies was one of five abalones targeted inthe California and Mexico fisheries; it is nowrare and protected from fishing. The biologicalcharacteristics of this deep-living abaloneindicate that it was particularly vulnerable toover-exploitation; reduction of density orgroup size is now known to lead to declines infertilization success and recruitment failure.Warning signs of potential problems existedboth pre- and post-exploitation but were notrecognized. In particular, serial depletion wasnot detected because catch was not analyzedspatially, perhaps because total landings werereasonably stable for the short period ofexploitation. Recent submersible surveys led toestimates that white abalone now number lessthan 2,600 animals or 0.1% of the estimatedpre-exploitation population size. Densities andestimated population sizes are less than 100animals, at all but one location. Alternateexplanations for the decline in abundance wereconsidered and only exploitation-linkedfactors, such as sub-legal mortality andillegal fishing, were likely contributors.Episodic recruitment appears to be acharacteristic of broadcast-spawning,long-lived species and may make themparticularly vulnerable to over-exploitation.Management strategies based on size limits thatallow a few years of spawning prior to reachingminimum legal size are insufficient.Sustainable fisheries will require multipleprotected areas to preserve brood stockaggregations necessary for successfulfertilization.     

Canadian Perceptions of Commercial Fisheries Management and Marine Mammal Conservation in the Northwest Atlantic Ocean

ABSTRACT

Public attitudes toward the use of fisheries and marine mammals in the northwest Atlantic have played an influential role in recent controversies over management of these resources. A thorough assessment of public sentiment has, however, been lacking. We describe the results of a survey conducted to assess Canadian public opinion regarding a variety of commercial fisheries and marine mammal issues. Over one thousand, randomly selected adult Canadians were surveyed concerning their attitudes, knowledge, and concerns toward the conservation and management of marine mammals in the northwest Atlantic. The sample included 875 members of the general public, 130 sealers and 81 commercial fishermen.

Most Canadians (93–95%) in all sampling groups and in all provinces, except Quebec (54%), expressed concern about conflicts between marine mammals and commercial fisheries. Knowledge of basic marine mammal biology, however, was strikingly deficient and variable among groups: sealers obtained the highest knowledge rating, fishers were intermediate, and the general public scored lowest. The views of the Canadian general public, sealers, and commercial fishers were highly divergent regarding prioritization of goals for Canada's commercial fishing industry. Sealers and fishers emphasized employment, cultural and economic considerations, while the general public placed greater emphasis on ecological and ethical matters. All groups agreed that the most significant threats to Canada's commercial fisheries included fishing by foreign countries, pollution, and over-fishing. Competition from marine mammals and damage to fishing equipment by marine mammals were rated as the least important threats. Fishing by foreign vessels in Canadian waters was regarded by all groups with particular suspicion.

Unlike sealers and fishers, the general public consistently disputed the notion of sacrificing the needs of marine mammals for the benefit of commercial fishing. The public also expressed a strong preference for including fishing impacts on marine mammals in setting allowable catch quotas for commercial fish stocks, and further indicated a willingness to favor the interests of marine mammals over commercial fisheries in marine mammal entanglement situations.

More than ninety percent of all respondents indicated strong support for the ‘existence value’ of seals. Most Canadians opposed sealing for fur, whereas most approved of harvesting abundant adult seal populations for meat, harvests associated with the cultures of native peoples, and harvests important to local economies. Respondents were divided regarding the harvest of seals that damage fishing gear. All groups strongly opposed the harvest of newborn seals. Sealers and residents of Newfoundland supported lethal methods of seal population control, while residents of large urban areas and women were inclined to approve of non-lethal measures. An overwhelming majority of Canadians objected to the use of poisons or clubs as a means of population control.

Consideration of the results of this study could provide an enhanced basis for fashioning mutually acceptable policy solutions and mitigating conflicts between commercial fisheries and marine mammal conservation in the northwest Atlantic Ocean.     

Due Diligence and Overlooked Evidence in the South China Sea Arbitration: A Note

Abstract

In the South China Sea Arbitration, the Tribunal decided that China had not breached the due diligence obligation to protect and preserve the marine environment under Articles 192 and 194(5) of the United Nations Convention on the Law of the Sea concerning Chinese fishers fishing with explosives, but that China had breached the same obligation regarding Chinese fishers harvesting endangered species. This article looks at how the Tribunal interpreted and applied the due diligence obligation and argues, from a Chinese perspective, that there were facts overlooked by the Tribunal that China could have presented to counter the evidence of the Philippines, which might have been enough to affect the decision on destructive fishing had China participated in the Arbitration.     

Weak Compliance Undermines the Success of No-Take Zones in a Large Government-Controlled Marine Protected Area

The effectiveness of marine protected areas depends largely on whether people comply with the rules. We quantified temporal changes in benthic composition, reef fish biomass, and fishing effort among marine park zones (including no-take areas) to assess levels of compliance following the 2005 rezoning of the government-controlled Karimunjawa National Park (KNP), Indonesia. Four years after the rezoning awareness of fishing regulations was high amongst local fishers, ranging from 79.5±7.9 (SE) % for spatial restrictions to 97.7±1.2% for bans on the use of poisons. Despite this high awareness and strong compliance with gear restrictions, compliance with spatial restrictions was weak. In the four years following the rezoning reef fish biomass declined across all zones within KNP, with >50% reduction within the no-take Core and Protection Zones. These declines were primarily driven by decreases in the biomass of groups targeted by local fishers; planktivores, herbivores, piscivores, and invertivores. These declines in fish biomass were not driven by changes in habitat quality; coral cover increased in all zones, possibly as a result of a shift in fishing gears from those which can damage reefs (i.e., nets) to those which cause little direct damage (i.e., handlines and spears). Direct observations of fishing activities in 2009 revealed there was limited variation in fishing effort between zones in which fishing was allowed or prohibited. The apparent willingness of the KNP communities to comply with gear restrictions, but not spatial restrictions is difficult to explain and highlights the complexities of the social and economic dynamics that influence the ecological success of marine protected areas. Clearly the increased and high awareness of fishery restrictions following the rezoning is a positive step. The challenge now is to understand and foster the conditions that may facilitate compliance with spatial restrictions within KNP and marine parks worldwide.     

Evaluating ecosystem structure and functioning of the East China Sea Shelf ecosystem,China

As China’s second-largest large marine ecosystem, the East China Sea Shelf has suffered from overfishing, eutrophication, and physical disturbance over the last several decades. A trophic mass-balance model of this ecosystem was developed in order to characterize the structure and functioning of its food web, to identify its keystone species, and to quantify the ecological impacts of fishing that it sustained during the early 2000s. Using a multivariate statistical analysis, we identified 38 functional groups for the trophic model, including fish and invertebrate groups targeted and not targeted by fisheries. Pelagic sharks and rays were identified as the keystone species in the ecosystem. Strong benthic–pelagic coupling was indicated in this ecosystem. In particular, this study highlighted the interdependent relationships that exist among plankton, benthic invertebrates, and detritus. Recent fishing activities were characterized by high exploitation rates for various commercially targeted and non-targeted species, leading to the removal of much of the ecosystem’s fishable production. Overall, our findings give a preliminary explanation of the current problems of eutrophication and fishery depletion and other changes in the East China Sea Shelf, and highlight the need for developing ecosystem-based fisheries management.     

Ethnotaxonomy of sharks from tropical waters of Brazil

Background

Accessing folk knowledge from small-scale fishers is an affordable and reliable approach to understand the dynamic and diversity of shark species worldwide, especially of those eventually caught. In this context, ethnotaxonomy (folk identification and classification) may represent an alternative to support sharks fisheries management, especially in data-poor places. This study aimed to investigate fishing and ethnotaxonomy of the main shark species caught by small-scale fisheries from the coastal waters of the Brazilian Northeast.

Methods

Semi-structured and structured interviews were conducted with fishers targeting general aspects of fishing activities and specific topics regarding ethnotaxonomy, capture, and commercialization of sharks. For species identification, an ethnobiological systematic perspective was used to analyze the folk nomenclature and classification criteria. Non-parametric statistical tests were used to verify associations between species caught, fishing gear, and harvest period.

Results

Fishers mentioned 73 binomial names, 21 main folk species, and eight synonymies. Some species belonging to the same scientific genus are often named and grouped by the same folk name, with no distinction between species by fishers. Sharks are most landed as bycatch and correspond to less than 5% of the total commercial fisheries in the communities, with socioeconomic value for subsistence consumption and local commercialization. Sharks were said to be mainly caught with hand line and surface long line during the rainy season, while gillnet captures were associated to the dry season. At least three of the species most mentioned by fishers are currently classified as vulnerable and endangered worldwide.

Conclusions

Even though landed sharks account for a small proportion of the fishing catches, their biological and life history features place sharks among the most vulnerable organisms globally. Such an ethnobiological approach towards shark identification may contribute to generate basic information on species caught, their frequency in the landings, and how different species belonging to the same genus can be landed and sold together. This type of information can generate subsidies to the development of conservation and management plans for these fishing resources, where knowledge is scarce.

     

Using behavior and ecology to exploit schooling fishes

By the late 1980's, humans were removing 76 million metric tons (MMT) of marine fishes annually. The potential sustainable catch is somewhere between 69 and 96 MMT. As a result, major fisheries have collapsed or are in danger of collapsing. Many of these species school. Schooling is effective against gape-limited predators because of dilution and confusion. However, larger predators may exploit schooling behavior to sequester and consume a non-trivial fraction of the group. This is the strategy of fishers. Both gear and fisher behavior have evolved to take advantage of the seemingly canalized response of schooling species. This paper examines the ways artisanal and western fishers have exploited knowledge of the behavior and ecology of schooling species to aid in fish capture. Topics include object association; use of light, sound, and chemicals; perceived barriers; predator-prey and other trophic interactions; inherent cyclical rhythms such as diel migration, lunar spawning, and seasonality; and correlations with the physical environment. Exploiting schooling allows fishers to increase efficiency through knowledge of when and where fish aggregate, or by extending the conditions under which aggregation occurs. However, knowledge of behavioral ecology can also be used to conserve schooling stocks. Gear selectivity, group size and population dynamics, and fisher efficiency are all potential areas of integration between behavioral ecology and fishery management. However, no amount of integration of behavioral ecology into fishery management will have the intended conservation effects if fishing effort is not limited to at least numerical if not behaviorally-sustainable levels.     

Management implications of the biodiversity and socio-economic impacts of shrimp trawler by-catch in Bahía de Kino, Sonora, México

The shrimp fishery is the most economically important fishery in Mexico. The trawler-based portion of this fishery results in high rates of by-catch. This study quantifies and describes the biodiversity of by-catch associated with trawling in the Bahía de Kino region of Sonora, Mexico. Data were collected from 55 trawls, on six boats, over 14 nights, during November of 2003, 2004, 2006-2009. By-catch rates within trawl samples averaged 85.9% measured by weight. A total of 183 by-catch species were identified during the course of this study, including 97 species of bony fish from 43 families, 19 species of elasmobranchs from 12 families, 66 species of invertebrates from eight phyla, and one species of marine turtle; seven of the documented by-catch species are listed on the IUCN Red List, CITES, or the Mexican NOM-059-ECOL-2010; 35 species documented in the by-catch are also targeted by local artisanal fishers. Some of the species frequently captured as juveniles in the by-catch are economically important to small-scale fishers in the region, and are particularly sensitive to overexploitation due to their life histories. This study highlights the need for further research quantifying the impacts of high levels of by-catch upon small-scale fishing economies in the region and presents strong ecological and economic rationale for by-catch management within the shrimp fishery of the Gulf of California. Site-specific by-catch management plans should be piloted in the Bahía de Kino region to address the growing momentum in national and international fisheries policy regimes toward the reduction of by-catch in shrimp fisheries.     

Globalization,marine regime shifts and the Soviet Union

Regime shifts have been observed in marine ecosystems around the world, with climate and fishing suggested as major drivers of such shifts. The global and regional dynamics of the climate system have been studied in this context, and efforts to develop an analogous understanding of fishing activities are developing. Here, we investigate the timing of pelagic marine regime shifts in relation to the emergence of regional and global fishing activities of the Soviet Union. Our investigation of official catch statistics reflects that the Soviet Union was a major fishing actor in all large marine ecosystems where regime shifts have been documented, including in ecosystems where overfishing has been established as a key driver of these changes (in the Baltic and Black Seas and the Scotian Shelf). Globalization of Soviet Union fishing activities pushed exploitation to radically new levels and triggered regional and global governance responses for improved management. Since then, exploitation levels have remained and increased with new actors involved. Based on our exploratory work, we propose that a deeper understanding of the role of global fishing actors is central for improved management of marine ecosystems.     

Composition of the Aboriginal harvest of fisheries resources in coastal New South Wales,Australia

A key aspect of equitable management of the world’s fishery resources is the provision of traditional fishing access for Indigenous peoples. In Australia, increased recognition of the importance of fisheries to Indigenous culture and livelihoods over recent years has created a need for information on the species targeted to support policy and management. In the State of New South Wales (NSW), research on Indigenous fisheries catch composition is limited to two major studies. Here, we compare and combine data on Indigenous catch composition from these two studies to produce a comprehensive synthesis of current knowledge of Indigenous fisheries in NSW. The species harvested include more than 150 species of finfish and invertebrates, over 90 % of which are also harvested by commercial and recreational fishers. Our findings provide an empirical basis for future development of policy and management initiatives to meet the needs of Indigenous fishers and other stakeholders, as well as the principles of sustainable fisheries harvest.     

Metamorphic Competence, a Major Adaptive Convergence in Marine Invertebrate Larvae

Larvae from diverse marine-invertebrate phyla are able to respondrapidly to environmental cues to settlement and to undergo veryrapid metamorphic morphogenesis because they share the developmentaltrait of metamorphic competence. The competent state, characteristicof larvae as diverse as those of cnidarian planulae, molluscanveligers, and barnacle cyprids, is one in which nearly all requisitejuvenile characters are present in the larva prior to settlement.Thus metamorphosis, in response to more or less specific environmentalcues (inducers), is mainly restricted to loss of larva-specificstructures and physiological processes. Competent larvae oftwo "model marine invertebrates" studied in the authors' laboratory,the serpulid polychaete Hydroides elegans and the nudibranchPhestilla sibogae, complete metamorphosis in about 12 and 20hr, respectively. Furthermore, little or no de novo gene actionappears to be required during the metamorphic induction processin these species. Contrasting greatly with the slow, hormonallyregulated metamorphic transitions of vertebrates and insects,competence and consequent rapid metamorphosis in marine invertebratelarvae are conjectured to have arisen in diverse phylogeneticclades because they allow larvae to continue to swim and feedin the planktonic realm while simultaneously permitting extremelyfast morphological transition from larval locomotory and feedingmodes to a different set of such modes that are adaptive tolife on the sea bottom.     

Estimation and interpretation of egg provisioning in marine invertebrates

Per-offspring maternal investment is an integral part of life-historytheory. To understand the evolution of per-offspring maternalinvestment in marine invertebrates, a number of mathematicalmodels have been developed. These models examine how selectionaffects the proportion of maternally derived egg energy usedto produce a newly metamorphosed juvenile (s) and make predictionsabout the distribution of s in nature. However, there are veryfew published values of s and therefore it is difficult to evaluatehow well these models match nature. We present several equationsto empirically estimate values of s for any group of marineinvertebrate, and use data from echinoderms to compare the differentequations. The calculations that directly estimate s requireinformation on the amount of egg energy, juvenile energy, andenergy metabolized during development. Currently, there arefew data available for directly estimating s, and thus generatingdistributions of s derived from direct estimates is not possible.Furthermore, the direct estimations of s are informative forplanktotrophy but not for lecithotrophy. We have developed anequation that can be used to directly estimate s for lecithotrophs.The calculations to indirectly estimate s only require egg energyor egg size for the species in question and the value of s andegg energy or size for a reference species. This reference speciesreplaces the need to measure juvenile energy and energy metabolizedduring larval development. Because egg energy or size is currentlyavailable for many species, the indirect estimates will be usefulfor generating distributions of s, and will allow comparisonswith models. Although these indirect methods are good for generatingdistributions of s, they do not provide reliable estimates ofs for any particular species. Estimating values of s to comparemodels is a critical gap in our current evaluations of marineinvertebrate life-history models.     

Costly signaling and torch fishing on Ifaluk atoll

In this paper I evaluate the merit of costly signaling theory (CST) as a paradigm for understanding why men of Ifaluk atoll torch fish. I argue that torch fishing is a handicap that signals men's productivity. Consistent with CST, torch fishing is observed by the predicted audience (women), energetically costly to perform, and a reliable indicator of the frequency a man fishes during the trade wind season. Contrary to expectations of who should benefit from torch fishing and consequently participate, torch fishers are not primarily young and unmarried. Torch fishers, however, are predominately from the matriline that owns the canoe on which they fish, suggesting that torch fishing also signals the productivity of a matriline. Although these results support the possibility that torch fishing is a handicap, no data are presented which demonstrate that torch fishers achieve any gains from sending the costly signal. This shortcoming and other directions for future research on Ifaluk foraging decisions are discussed.     

Architecture of collapse: regime shift and recovery in an hierarchically structured marine ecosystem

By the late 20th century, a series of events or ‘natural experiments’, for example the depletion of apex predators, extreme eutrophication and blooms of invasive species, had suggested that the Black Sea could be considered as a large ecosystem ‘laboratory’. The events resulted in regime shifts cascading through all trophic levels, disturbing ecosystem functioning and damaging the water environment. Causal pathways by which the external (hydroclimate, overfishing) and internal (food web interactions) drivers provoke regime shifts are investigated. Statistical data analyses supported by an interpretative framework based on hierarchical ecosystem theory revealed mechanisms of hierarchical incorporation of environmental factors into the ecosystem. Evidence links Atlantic teleconnections to Black Sea hydroclimate, which together with fishing shapes variability in fish stocks. The hydroclimatic signal is conveyed through the food web via changes in productivity at all levels, to planktivorous fish. Fluctuating fish abundance is believed to induce a lagged change in competitor jelly plankton that cascades down to phytoplankton and influences water quality. Deprived of the stabilising role of apex predators, the Black Sea's hierarchical ecosystem organisation is susceptible to both environmental and anthropogenic stresses, and increased fishing makes fish stock collapses highly probable. When declining stocks are confronted with burgeoning fishing effort associated with the inability of fishery managers and decision‐makers to adapt rapidly to changes in fish abundance, there is overfishing and stock collapse. Management procedures are ineffective at handling complex phenomena such as ecosystem regime shifts because of the shortage of suitable explanatory models. The proposed concepts and models reported here relate the hydroclimate, overfishing and invasive species to shifts in ecosystem functioning and water quality, unravelling issues such as the causality of ecosystem interactions and mechanisms and offering potential for finding ways to reverse regime shifts. We advocate a management approach aiming at restoring ecosystem hierarchy that might mitigate the costly consequences of regime shifts.     

Rapidly shifting environmental baselines among fishers of the Gulf of California

Shifting environmental baselines are inter-generational changes in perception of the state of the environment. As one generation replaces another, people's perceptions of what is natural change even to the extent that they no longer believe historical anecdotes of past abundance or size of species. Although widely accepted, this phenomenon has yet to be quantitatively tested. Here we survey three generations of fishers from Mexico's Gulf of California (N=108), where fish populations have declined steeply over the last 60 years, to investigate how far and fast their environmental baselines are shifting. Compared to young fishers, old fishers named five times as many species and four times as many fishing sites as once being abundant/productive but now depleted (Kruskal-Wallis tests, both p<0.001) with no evidence of a slowdown in rates of loss experienced by younger compared to older generations (Kruskal-Wallis test, n.s. in both cases). Old fishers caught up to 25 times as many Gulf grouper Mycteroperca jordani as young fishers on their best ever fishing day (regression r(2)=0.62, p<0.001). Despite times of plentiful large fish still being within living memory, few young fishers appreciated that large species had ever been common or nearshore sites productive. Such rapid shifts in perception of what is natural help explain why society is tolerant of the creeping loss of biodiversity. They imply a large educational hurdle in efforts to reset expectations and targets for conservation.     

Biodiversity of Coral Reefs: What are We Losing and Why?

SYNOPSIS. Coral reefs are threatened by numerous anthropogenicimpacts, some of which have already had major effects worldwide.These unique tropical environments harbor a high diversity ofcorals, reef invertebrates, fish and other animals and plants.In most taxa, the species diversity of reef-associated organismsis poorly understood because many of the species have yet tobe collected and described. High coral mortality has been associatedwith natural events such as hurricanes, predator outbreaks andperiods of high temperature, but has also resulted from excessnutrients in sewage and from specific pollutants. Reef coralsand associated organisms are also threatened by the possibilityof global warming which will result in rising sea levels andperiods of increased temperature stress, and which may alsobring increased storm frequency and intensity. Although therecent extensive episodes of coral bleaching in the Caribbeanand eastern Pacific cannot be causally related to global warmingat this time, the close link between bleaching and temperaturesuggests that global warming will result in severe changes incoral assemblages. Major reef destruction has followed outbreaksof the predatory seastar Acanthaster planci in the Pacific.Although this is considered part of a natural disturbance cycle,there are indications that altered land use patterns and reductionof predators on this seastar by human activities may have increasedthe severity of outbreaks. Recreational and commercial use ofreefs has also increased, and has caused extensive damage, especiallynear areas of high population density. One of the most obviousand widespread losses to reef biota is the reduction in fishpopulations from intense overfishing in most reef areas of theworld. Coasts without adequately managed reefs have sufferedintense overfishing for both local and export purposes, to thepoint where the positive effects of fish on those reefs havebeen compromised. The combination of these destructive factorshas altered reefs in all localities, and many that were onceconsidered protected by distance and low population densityare now being exploited as well. On the positive side, improvedunderstanding of ecological processes on reefs combined withconcerted conservation efforts have managed to protect someextensive areas of reef for the future.     

Assessing the potential biological implications of recreational inshore fisheries on sub‐tidal fish communities of Azores (north‐east Atlantic Ocean) using catch and effort data

Recreational inshore fishing activities practiced on Faial and Pico Islands (Azorean archipelago) were surveyed between October 2004 and September 2005. Recreational inshore fishers employ three main methods of fishing (shore angling, spear fishing and intertidal collecting). The method that demanded the highest fishing effort (number of fishing operations) was shore angling, followed by intertidal collecting and spear fishing. Shore angling produced the highest diversity of catch composition (38), which is in part explained by the seven fishing techniques used by shore anglers. The estimates of annual catch were higher for shore angling than spear fishing (51·2 and 6·3 t) even though they were lower than commercial artisanal fishing (442 t). The weighted mean trophic level and vulnerability index values in the fish catch were higher for spear fishing (3·4 and 50·9) than for shore angling (3·1 and 44·5). Cumulative pressure by different recreational fishing activities was detected on species already subject to a heavy pressure from Azorean commercial fishing, and on vulnerable and top‐predator species. There are important biological and ecological implications whereby fishery managers should implement additional regulations such as prohibiting catches of the most vulnerable species.