The purpose of this study is to challenge long-standing assumptions on Atlantic cod (Gadus morhua) feeding around Newfoundland and Labrador, Canada, and provide information that will be useful for the next generation of ecosystem-based models. Using stomach content analysis and published cod stomach data I address two primary questions: Do cod cease feeding during spawning? Does the cod diet reflect changes in prey assemblages in the ecosystem? Spatial and temporal diet variation was additionally analyzed. Regional variation was paramount such that diet diversity, mirroring ecosystem diversity, increased with decreasing latitude. Contrary to current assumptions, feeding continued through spawning. The stomach content contribution of shrimp reflect environmental trends in these prey assemblages over the past 65 years, while crab, a minor part of the cod diet, does not reflect abundance changes. Capelin appeared preferably consumed when encountered. Cod are not complete generalist feeders but select for certain energy rich prey.
This manual aims to enhance policymakers’ understanding of the standardised methodology for the valuation and accounting of island ecosystem services, taking into consideration the unique environmental, socio-economic and capacity issues relevant to SIDS.
Marine dredging is an excavation activity carried out worldwide by many industries. Concern about the impact dredging has on marine life, including marine mammals (cetaceans, pinnipeds, and sirenians) exists, but effects are largely unknown. Through consulting available literature, this review aims to expand on existing knowledge of the direct and indirect, negative and positive impacts on marine mammals. In terms of direct effects, collisions are possible, but unlikely, given the slow speed of dredgers. Noise emitted is broadband, with most energy below 1 kHz and unlikely to cause damage to marine mammal auditory systems, but masking and behavioural changes are possible. Sediment plumes are generally localized, and marine mammals reside often in turbid waters, so significant impacts from turbidity are improbable. Entrainment, habitat degradation, noise, contaminant remobilization, suspended sediments, and sedimentation can affect benthic, epibenthic, and infaunal communities, which may impact marine mammals indirectly through changes to prey. Eggs and larvae are at highest risk from entrainment, so dredging in spawning areas can be detrimental, but effects are minimized through the use of environmental windows. Sensitive environments such as seagrass beds are at risk from smothering, removal, or damage, but careful planning can reduce degradation. Assessing impacts of contaminant remobilization is difficult, but as long as contaminated sediments are disposed of correctly, remobilization is limited in space and time. Effects of suspended sediments and sedimentation are species-specific, but invertebrates, eggs, and larvae are most vulnerable. Positive effects, including an increase in food, result from greater nutrient loads, but are often short term. Dredging has the potential to impact marine mammals, but effects are species and location-specific, varying also with dredging equipment type. In general, evidence suggests that if management procedures are implemented, effects are most likely to be masking and short-term behavioural alterations and changes to prey availability.
The objective of the Common Fisheries Policy (CFP) of the European Union is to assure sustainable exploitation of the live aquatic resources and aquaculture in the context of sustainable development considering in a balanced way the environmental, economic and social considerations. Poland as a Member State of the European Union has access to structural funds. Activities financed by the EU through the Fisheries Local Action Groups (FLAGs), i.e. entities associating representatives of widely understood fisheries sector, communes and other public and civic sector entities, that is voluntary associations operating in the areas dependent on fisheries have the largest opportunities for implementing the assumptions of the Common Fisheries Policy.
The Fisheries Local Action Groups in Poland are the operators of the Operational Programme “Sustainable Development of the Fisheries Sector and Coastal Fishing Areas 2007-2013” [OP FISH 2007 – 2013] within the framework of priority axis 4 “Sustainable development of fisheries areas”. In the country 48 Fisheries Local Action Groups operate of which 9 are based on access to the Baltic Sea. The amount of over EUR 313 million has been allocated for implementation of priority axis 4 of the OP FISH 2007-2013. This represents ca. 32% of the funds allocated for financing of the entire Operational Programme “Sustainable Development of the Fisheries Sector and Coastal Fishing Areas 2007-2013”.
According to the assumptions, the activities of FLAGs are to contribute to stimulation of the communities in areas dependent on fisheries by including social and economic partners from the defined area in planning and implementation of local initiatives. The paper presents the outcomes and Polish experiences from operation of the FLAGs (FLAG operation principles, projects implemented, absorption of funds allocated to financing individual types of activities within the activities of sea coast FLAGs). An attempt will also be undertaken at evaluating the outcomes from implementation of individual actions and Union funds absorption in the maritime fisheries sector resulting from activities of the Fisheries Local Action Groups. The analysis covers the years of the current financial perspective 2007-2013.
The results of studies presented in the paper concerning the outcomes from implementation of the individual projects by the FLAGs will be based on the data obtained from the Ministry of Agriculture and Rural Development originating directly from selected Fisheries Local Action Groups and own field studies. Analysis covers the current financial perspective, i.e. the period of 2007-2013. Within the framework of the studies an attempt was also undertaken at determining whether a correlation exists between implementation of operations within the priority axis 4 of the OP FISH and the improvement of socioeconomic situation of the population covered by the Fisheries Local Action Groups. The Hellwig method (1968) was applied to determine the level of socioeconomic development. Indicators concerning the demographic-social, economic and related to technical and social infrastructure domains elaborated based on the data of the Central Statistical Office for the years 2004 and 2012 were applied.
Southern Bering Sea fishermen are vulnerable to losing access to key fisheries due largely to policy changes, permit loss, and the expense of fishing operations. Local residents generally do not have fishing rights in many of the high value commercial fisheries. They must continuously shape policy and explore alternative economies in order to stay fishermen. We were contracted by the U.S. Bureau of Ocean Energy Management to study the role of subsistence and commercial fisheries, land use, socioeconomics, and sharing networks in Alutiiq and Aleut/Unangan villages. Through an exploration of these data using innovative social network analysis that presents relationships, social stratification, commercialisation, and other dependencies in the maintenance of fisheries, sharing, trading, and revenue streams, this paper shows that in two of the most socioeconomically valuable fisheries, king crab (Paralithodes sp. and Lithodes sp) and cod (Gadidae), local peoples have had to gain access to these foods by using means outside of what are academically perceived as their traditional subsistence and commercial allocation, resulting in adaptive networks of distribution. This work shows the range of networks surrounding these key foods and their associated vulnerabilities and resilience. Those sharing networks that demonstrate greater interconnectedness are much more stable and resilient.
Marine spatial planning (MSP) has emerged as a highly promoted approach to implementing integrated management of coastal and ocean areas. It is linked to ecosystem-based management (EBM), the ecosystem approach to fisheries (EAF), geographic information systems (GIS), marine protected areas (MPAs) and more. Although MSP has gained global attention, its use appears to be less prominent in small island developing states (SIDS) and other developing countries than in developed countries. The purpose of this paper is to discuss the implications and practical application of MSP as an ocean resource management paradigm in Asia and the Caribbean. Where will MSP fit in the range of management paradigms? Where and how can it be best utilized for integrated resource management? What are challenges for implementation? Examples of use of MSP and marine zoning are presented and discussed.
These Voluntary Guidelines for Securing Sustainable Small-Scale Fisheries in the Context of Food Security and Poverty Eradication have been developed as a complement to the 1995 FAO Code
of Conduct for Responsible Fisheries (the Code). They were developed to provide complementary guidance with respect to small-scale fisheries in support of the overall principles and provisions of the Code. Accordingly, the Guidelines are intended to support the visibility, recognition and enhancement of the already important role of small-scale fisheries and to contribute to global and national efforts towards the eradication of hunger and poverty. The Guidelines support responsible fisheries and sustainable social and economic development for the benefit of current and future generations, with an emphasis on small- scale fishers and fish workers and related activities and including vulnerable and marginalized people, promoting a human rights- based approach.
It is emphasized that these Guidelines are voluntary, global in scope and with a focus on the needs of developing countries.
Congress passed the Endangered Species Act of 1973 (16 USC 1531 et seq., amended 1978, 1982, 1986, 1988) (ESA) to protect species of plants and animals endangered or threatened with extinction. The National Oceanic and Atmospheric Administration’s (NOAA) National Marine Fisheries Service (NMFS) and the U.S. Fish and Wildlife Service (FWS) share responsibility for the administration of the ESA. NMFS is responsible for most marine and anadromous species including the elkhorn coral (Acropora palmata) and the staghorn coral (A. cervicornis).
NMFS listed both the elkhorn coral and the staghorn coral as threatened on May 9, 2006. Section 4(f) of the ESA directs NMFS and FWS to develop and implement recovery plans for species under their jurisdiction, unless such a plan would not promote the species’ conservation. NMFS determined that a recovery plan would promote conservation of elkhorn and staghorn corals and assembled the Acropora Recovery Team (ART) to develop this recovery plan. The ART included coral scientists and management experts from state, territorial, and federal government agencies and the non-governmental sector.
NMFS agrees with the ART that the success of the Acropora recovery plan will depend on cooperation from state, territorial, and federal agencies and a long-term commitment to implementing and enforcing its recommendations.
Fish hold effluent and the effluent produced from the cleaning of fish holds may contain organic material resulting from the degradation of seafood and cleaning products (e.g., soaps and detergents). This effluent is often discharged by vessels into near shore waters and, therefore, could have the potential to contribute to water pollution in bays and estuaries. We characterized effluent from commercial fishing vessels with holds containing refrigerated seawater, ice slurry, or chipped ice. Concentrations of trace heavy metals, wet chemistry parameters, and nutrients in effluent were compared to screening benchmarks to determine if there is a reasonable potential for effluent discharge to contribute to nonattainment of water quality standards. Most analytes (67%) exceeded their benchmark concentration and, therefore, may have the potential to pose risk to human health or the environment if discharges are in significant quantities or there are many vessels discharging in the same areas.
In this study, we analyse seasonal aspects of harbour porpoise strandings in the Sea of Azov and discuss factors affecting the stranding rate. Data on 633 strandings were obtained from monitoring of a 35-km long area of the south coast of the Sea of Azov in 1999–2013. A distinct peak of strandings fell in July and August: it depended on the bycatch peak and calving season. Stranding rates depended neither on weather conditions nor on the seasonal fishing activities (including IUU fisheries). Moreover, stranding peaks in the neighbouring Black Sea were also tied to the calving season rather than to the fishing activities. We suggest that the seasonal mortality patterns are indirectly determined by nutritional stress: in Atlantic, winter-stranding oceanic populations and summer-stranding inner-sea populations occur that also possibly differ in the seasonal dynamics of body mass, weaning time or duration of mother–calf association, and dentine structure. In a typical summer-stranding population, summer is the season of nutritional stress, parturition, independent foraging of yearlings and lactation of nursing females, which leads to the risky foraging behaviour near gillnets. Another possible factor of increased bycatch is the seasonal habitat preference, corresponding to the gillnet preferences. Therefore, stranding and bycatch seasonality of porpoises can largely be explained by the aspects of their life history and foraging behaviour rather than by weather conditions and fisheries. This supports the time–area closure strategy as an adequate conservation measure, which would consider minimizing the conflict of interest with fisheries.
Selectivity has traditionally been well estimated internally in stock assessment models when length or age composition data are available. However, in stock assessment, temporal or spatial variation in fishery or stock structure can lead to misspecification of the selectivity pattern, which can contribute substantially to the uncertainty in stock assessment results. Consequently, generating auxiliary information to help stock assessment scientists avoid unrealistic specifications of selectivity patterns should be encouraged. Here, we combine data from pop-up satellite archival tags (PSATs) deployed on blue sharks in the South Atlantic Ocean, and information on maximum pelagic longline fishing depths, to introduce an alternative approach for estimating selectivity of fishing gear. Further, we present how this externally estimated tag-based selectivity can be used to inform the most appropriate form of selectivity curves (e.g. asymptotic or dome-shaped) in a spatially structured stock assessment model for the South Atlantic blue shark population. The estimated tag-based selectivity showed substantially different selectivity patterns within the area of the assessed stock, in one area the depth range of the longline gear is inhabited mostly by adults, which is consistent with an asymptotic selectivity. In another area, the overlap shifts to younger ages, with older sharks located in deeper waters, consequently the expected selectivity is more dome-shaped. To account for this variability in the stock assessment model, we assigned fishing fleets with different selectivity patterns. The form of the selectivity curve assigned for each fleet was based on the tag-based selectivity estimates for the area of where that fleet operates. The assessment model demonstrated relatively good fit to the data and that the estimated management quantities were robust. This study provides additional evidence that externally derived estimates of selectivity using PSATs data can assist implementing stock assessments that capture some of the spatial variability of pelagic fish species.
Species distribution models (SDMs) are important tools to explore the effects of future global changes in biodiversity. Previous studies show that variability is introduced into projected distributions through alternative datasets and modelling procedures. However, a multi-model approach to assess biogeographic shifts at the global scale is still rarely applied, particularly in the marine environment. Here, we apply three commonly used SDMs (AquaMaps, Maxent, and the Dynamic Bioclimate Envelope Model) to assess the global patterns of change in species richness, invasion, and extinction intensity in the world oceans. We make species-specific projections of distribution shift using each SDM, subsequently aggregating them to calculate indices of change across a set of 802 species of exploited marine fish and invertebrates. Results indicate an average poleward latitudinal shift across species and SDMs at a rate of 15.5 and 25.6 km decade−1 for a low and high emissions climate change scenario, respectively. Predicted distribution shifts resulted in hotspots of local invasion intensity in high latitude regions, while local extinctions were concentrated near the equator. Specifically, between 10°N and 10°S, we predicted that, on average, 6.5 species would become locally extinct per 0.5° latitude under the climate change emissions scenario Representative Concentration Pathway 8.5. Average invasions were predicted to be 2.0 species per 0.5° latitude in the Arctic Ocean and 1.5 species per 0.5° latitude in the Southern Ocean. These averaged global hotspots of invasion and local extinction intensity are robust to the different SDM used and coincide with high levels of agreement.
We review three broad categories of risk assessment methodology used for cartilaginous fish: productivity-susceptibility analysis (PSA), demographic methods, and quantitative stock assessments. PSA is generally a semi-quantitative approach useful as an exploratory or triage tool that can be used to prioritize research, group species with similar vulnerability or risk, and provide qualitative management advice. Demographic methods are typically used in the conservation arena and provide quantitative population metrics that are used to quantify extinction risk and identify vulnerable life stages. Stock assessments provide quantitative estimates of population status and the associated risk of exceeding biological reference points, such as maximum sustainable yield. We then describe six types of uncertainty (process, observation, model, estimation, implementation, and institutional) that affect the risk assessment process, identify which of the three risk assessment methods can accommodate each type of uncertainty, and provide examples mostly for sharks drawn from our experience in the United States. We also review the spectrum of stock assessment methods used mainly for sharks in the United States, and present a case study where multiple methods were applied to the same species (dusky shark, Carcharinus obscurus) to illustrate differing degrees of model complexity and type of uncertainty considered. Finally, we address the common and problematic case of data-poor bycatch species. Our main recommendation for future work is to use Management Strategy Evaluation or similar simulation approaches to explore the effect of different sources of uncertainty, identify the most critical data to satisfy predetermined management objectives, and develop harvest control rules for cartilaginous fish. We also propose to assess the performance of data-poor and -rich methods through stepwise model construction.
Juvenile fish of >20 different species use offshore floating sea cages as settlement habitats in the Mediterranean Sea. In the present work, surveys were conducted to identify differences between species composition and abundance of new settlers among farms and control rocky-shore environments and to test for variation in their diets. Along with this, otolith growth and morphology analyses were also applied to better understand the consequences for the ecology and growth performance of several fish species that use coastal farms as recruitment habitats in the southwestern Mediterranean Sea. Results showed that fish farms are acting as a new habitat for the settlement of juvenile fish and that detected abundance could be compared with that found at natural habitats such as shallow rocky environments. However, a consistent pattern for all the studied species was a significant variation in otolith-shape descriptors, principally identified through the Aspect Ratio index, which was lower for the farm-associated species Atherina boyeri, Oblada melanura, and Sarpa salpa. Otolith modifications were effectively detected by elliptic Fourier descriptors since multivariate analysis correctly identified farm or control origin at 78.8, 85.1, and 86.1% for A. boyeri, O. melanura, and S. salpa individuals, respectively. According to these results, fish farms may offer new settlement habitat for several fish species on open coastal areas and provide resources equivalent to rocky habitats, but at the same time causing some effect on fish growth as a potential consequence of the availability of particulate organic matter derived from feed pellets.
The Newfoundland Shelf supported one of the world’s greatest fisheries until the main commercial species collapsed more than two decades ago. We calculated three ecological indices for individual populations and five for community from the data obtained in the research surveys conducted by Spain in NAFO Regulatory Area Divisions 3NO between 2002 and 2013. We use data for 24 species to study the dynamics of major demersal fish assemblages (38–300, 301–600, and 601–1460 m depth) and evaluated how they have responded to different levels of exploitation. Trends and changes for individual populations (abundance and biomass, intrinsic population rate of growth, and mean length) and for all the community (ABC curves, indices of faunal diversity, proportion of non-commercial species, mean length in community and size spectra) were used to test ecological trends. Indices showed no homogeneous status and responded to different exploitation patterns, management, and environmental regimes in each assemblage. Our results show an improvement in the shallower and deeper assemblages and that fishing effort does not explain differences among each assemblage.
Many fished stocks show long-term reductions in adult body size. Such changes could lead to new feeding interactions and alter stock productivity, introducing new levels of uncertainty in fisheries management. We use a marine ecosystem model parameterized for Southeast Australia to explore how reductions (up to 6% in 50 years) in size-at-age of fished species affect stock recovery after an implementation of a fishing moratorium. We show that reduction in body size can greatly elevate predation mortality and lower the post-fishing biomass of affected species. In our simulations, the recovery period after the fishing moratorium was characterized by two phases. In the initial readjustment phase, the ecosystem dynamics was largely determined by the rapid changes in the biomasses of recovering species and changes in body size had negligible effects. In contrast, fish body sizes had the major impact on the biomasses in the second, semi-equilibrium state and the final biomasses were generally not affected by the harvest rate during the fishing period. When reduced size-at-age elevated predation mortality in most age groups of a species (tiger flathead Platycephalus richardsoni or silver warehou Seriolella punctata in our simulations), the species' equilibrium biomass was considerably lower compared with the scenarios of no change in body size. For other species (pink ling Genypterus blacodes and jackass morwong Nemadactylus macropterus), a predation increase in some age groups was balanced by the decrease in others. The latter reduction in predation mortality occurred when major predators of species with reducing size-at-age were decreasing in size themselves, or when cannibalism was an important source of juvenile mortality (in blue grenadier Macruronus novaezelandiae). We suggest that decreased size-at-age will be most detrimental to stock recovery when the main predators of the stock are not affected by the drivers causing changes in body size.
A development of the ecological risk screening (ERS) technique, scale intensity and consequence analysis (SICA), is described and application to the varied fisheries and ecosystem off the southwest of England on behalf of an industry steering group (SG) is summarized. The purpose was to prioritize ecological risks systematically and consistently in relation to policy goals agreed by the SG. Scientists listed and advised on ecosystem components, their units (individual species, stocks, habitats, or communities) and attributes, as well as agents of change in the SW, their activities, and generalized effects relevant to the policy goals. A working group (WG) of fishers, fishery observers, technical advisors, and marine scientists paired each unit with the activity thought most likely to impact the most sensitive policy goal, then scored risk according to defined rules spatially, temporally, and as intensity and duration of effects. The geometric mean of the four scores, slightly adjusted for unscored factors if necessary, was the relative impact score (RIS). With this standardized method, the main aspects of risk were considered separately and independently, thereby assisting objective prioritization. Nineteen unit–activity pairs were listed as priority risks (RIS >3) in the SW region during a 2-d meeting that fully exploited the wide range of information and experience available at the WG. Socio-economics was not considered. The ERS for the SW was designed to be compatible with other similar ERSs that might be carried out for neighbouring marine regions. ERS can minimize extra monitoring needed for ecosystem management and, in principle, collaborating non-fishery agents of change could be included. By engaging all stakeholders in the setting of initial priorities for action and by assembling all available sources of information, ERS offers a useful starting point for holistic ecosystem management.
The North Sea brown shrimp fishery is currently regulated neither with quotas nor with effort management. The current paradigm of non-management was based on an analysis of the total predation by cod and whiting in relation to commercial catches for the period 1970–1995 and the estimated total dominance of natural mortality. However, since this period, the North Sea ecosystem has undergone pronounced changes with overfishing and climate change causing a substantial decline in predator stocks, namely cod and whiting. In addition, both predators have shifted their range of distribution causing a reduced overlap with brown shrimp. Here, we extend the previous assessment of brown shrimp predation for the years 1996–2011 using updated stock assessment and predator distribution data. For the first time, predation estimates are used together with commercial landings to partition independent estimates of total mortality into fishing and predation mortality. We demonstrate that the decline of key predators of brown shrimp in combination with a shift in the distributional range of the predators has caused a new situation, in which the fishery has become the main mortality source of adult brown shrimp (>50 mm). Average landings since 2000 have been ∼40% higher than in the 1980s and 1990s, indicating that humans have at least partly taken over the share previously taken by juvenile whiting and cod. We discuss that this situation is likely to continue, because three marine mammal species have built up a combined population of over 80 000 individuals, which hunt for potential brown shrimp predators mainly in the distribution area of brown shrimp. The application of two yield-per-recruit models of different complexity indicates potential growth overfishing of brown shrimp and reopens the discussion of management.
Coastal fisheries and sea cage aquaculture coexist along the coastal zone, and it has been suggested that wild fish feed on excess feed around farms. If this occurs, the condition of wild fish can increase and their lipid profile can become modified. However, the influence of fishfarming on coastal fisheries has not been described in detail. Four targeted species of different trophic gilds, Sardinella aurita, Caranx rhonchus, Mullus barbatus, and Pomatomus saltatrix were studied and the lipid profiles of individuals captured by coastal fisheries and around fish farms were compared. Results show that fish captured at farms showed increased levels of total lipids and/or the terrestrial fatty acids contained in feed pellets. Individuals with increased terrestrial fatty acid proportions were detected in the catch of small-scale artisanal fisheries but not among trawled fish. Consequently, this study demonstrates the influence of fishfarming on coastal fisheries through the exportation of excess feed in the shape of wild fish biomass.
Population structuring in the northern shrimp (Pandalus borealis) in the North Sea area (including Fladen and Skagerrak) was studied by microsatellite DNA analyses. Screening 20 sample locations in the open ocean and Skagerrak fjords for nine loci revealed low, but significant genetic heterogeneity. The spatial genetic structure among oceanic samples of Skagerrak and the eastern North Sea was weak and non-significant, consistent with the current management regime of one single stock. However, Skagerrak fjord samples generally displayed elevated levels of genetic differentiation, and significantly so in several pairwise comparisons with other fjords and oceanic samples. Although the Skagerrak fjord populations are of less economic value, some of them are regulated separately (e.g. the Gullmarsfjord) and local stocks may prove important to uphold genetic variability and biocomplexity in a changing environment.