Fishery Landings Research Articles

Towards coherent GES assessments at sub-regional level: signs of fisheries expansion processes in the Bay of Biscay using an OSPAR food web indicator, the mean trophic level

Abstract Using the Bay of Biscay (BoB) as a case study, we conducted a transnational assessment of the mean trophic level (MTL, Ospar FW4) indicator at sub-regional level, over the last three decades. Our results confirm the apparent recovery of BoB’s bentho-demersal system, as shown by trends in the MTL indicator based on survey data. However, they also point at a concomitant “fishing through” process where the apparent stability revealed by the MTL indicator based on landed catch data may be masking the expansion of demersal fisheries to deeper waters, and an over-exploitation of resources (particularly abundant pelagic species). Moreover, they show how the combined examination of independent surveys and fishery landings allows the identification of ecological trends in ecosystem studies. In addition, our results confirm that analysing MTL at various threshold levels helps discerning the causality of trends in this indicator, especially if analyses for pelagic and demersal species are run independently. Further studies, at smaller (i.e. local) spatial scales, need to be conducted to ascertain our results and suggest appropriate management strategies aimed at regulating fisheries expansions in the area.

Analysis of Long and Short Terms Fishery Landings of Köyceğiz Lagoon (Turkey)

Analysis of Long and Short Terms Fishery Landings of Köyceğiz Lagoon (Turkey)

Managing Local Stressors for Coral Reef Condition and Ecosystem Services Delivery Under Climate Scenarios.

Coral reefs provide numerous ecosystem goods and services, but are threatened by multiple environmental and anthropogenic stressors. To identify management scenarios that will reverse or mitigate ecosystem degradation, managers can benefit from tools that can quantify projected changes in ecosystem services due to alternative management options. We used a spatially-explicit biophysical ecosystem model to evaluate socio-ecological trade-offs of land-based vs. marine-based management scenarios, and local-scale vs. global-scale stressors and their cumulative impacts. To increase the relevance of understanding ecological change for the public and decision-makers, we used four ecological production functions to translate the model outputs into the ecosystem services: “State of the Reef,” “Trophic Integrity,” “Fisheries Production,” and “Fisheries Landings.” For a case study of Maui Nui, Hawai’i, land-based management attenuated coral cover decline whereas fisheries management promoted higher total fish biomass. Placement of no-take marine protected areas (MPAs) across 30% of coral reef areas led to a reversal of the historical decline in predatory fish biomass, although this outcome depended on the spatial arrangement of MPAs. Coral cover declined less severely under strict sediment mitigation scenarios. However, the benefits of these local management scenarios were largely lost when accounting for climate-related impacts. Climate-related stressors indirectly increased herbivore biomass due to the shift from corals to algae and, hence, greater food availability. The two ecosystem services related to fish biomass increased under climate-related stressors but “Trophic Integrity” of the reef declined, indicating a less resilient reef. “State of the Reef” improved most and “Trophic Integrity” declined least under an optimistic global warming scenario and strict local management. This work provides insight into the relative influence of land-based vs. marine-based management and local vs. global stressors as drivers of changes in ecosystem dynamics while quantifying the tradeoffs between conservation- and extraction-oriented ecosystem services.

Effects of the invasive green crab (Carcinus maenas) on American lobster (Homarus americanus): Food acquisition and trapping behaviour

The American lobster (Homarus americanus) is the most commercially important crustacean species in Eastern Canada. Fishery landings in Placentia Bay, Newfoundland have decreased steadily following the cod moratorium in 1992, with another noticeable drop in 2002 when the first invasion of the European green crab (Carcinus maenas) was likely to have happened. The effect of green crabs on the food consumption and catchability of lobsters was quantified in relation to crab density (n = 0, 1, 5, 25) and water temperature (4 °C, 12 °C). Food acquisition and behavioural responses of lobsters were unaffected by the water temperature or crab densities of 1 to 25 animals. However, when a lobster was pitted against 150 crabs they were unable to obtain any food and the crabs consumed all the food within 8 min. In contrast to lobsters, the green crabs consumed more food at the higher temperature because they were more active. As crab density increased the number of agonistic interactions and retreat behaviours increased at both temperatures, and crabs were more likely to retreat from a lobster than vice versa. The effects of green crabs on the catchability of lobsters around a baited trap was also investigated when crabs were freely mobile outside the trap or contained within the trap. Lobsters were more likely to approach and enter the trap at 12 °C than at 4 °C, however, they were also more likely to escape. Lobsters were less likely to approach or enter a trap if they interacted with crabs outside the trap. The present results suggest that interactions between green crabs and adult lobsters may influence lobster catch rates in Newfoundland.

Distribution of deep-water corals, sponges, and demersal fisheries landings in Southern California, USA: implications for conservation priorities.

Deep-sea corals in Southern California are diverse and abundant but subject to multiple stressors, including bottom-contact fisheries using mobile and fixed gear. There is a need for more information on the distribution of these taxa in relation to the distribution of demersal fishing effort, and the distribution of marine protected areas, in order to improve spatial planning. There are many marine managed areas in Southern California, including essential fish habitat (EFH) areas, conservation areas, and a national marine sanctuary, but specific areas of overlap between bottom fishing and benthic epifauna are poorly known. Groundfish surveys were conducted by the National Marine Fisheries Service using a remotely operated vehicle throughout Southern California between 2003 and 2011 to document abundance and distribution of deep-water rockfish and flatfish to a depth of 500 m. Corals and sponges were also common in these images, providing an opportunity to examine these communities. Analyses of 34,792 still images revealed abundance and diversity of coral and sponge taxa, as well as frequency of fishing debris. The occurrence data were overlaid in a geographic information system with landings data for deep-water (>50 m) demersal fisheries to identify areas of spatial overlap. Corals or sponges were observed in 23% of images. A total of 15 coral genera and six sponge morphotypes were identified. A total of 70 species codes were targeted by deep-water demersal fisheries operating below 50 m for years 2007–2011. A novel priority-setting algorithm was developed to identify areas of high richness, abundance, and fishing intensity (RAFi). Several highly-ranked areas were already protected as EFH (Footprint, Piggy Bank). Other highly-ranked sites (West Catalina Island, San Clemente Island, 9-Mile Bank, Santa Rosa Flats) were encompassed by transient gear restrictions, such as Rockfish conservation areas, but are now recommended for permanent protection by the Pacific Fishery Management Council.

Oysters, Sustainability, Management Models, and the World of Reference Points

This review focuses on the eastern oyster Crassostrea virginica and its pathogen Perkinsus marinus, but the reference points considered are applicable to a wide range of sessile hosts suffering significant mortality from disease. The biological characteristics and imperatives that constrain the deduction of reference points are first reviewed. This is followed by a review of the various models and their reference points that have been implemented or considered in an effort to sustainably manage C. virginica stocks. The last section evaluates the application of reference points addressing maximum sustainable yield (msy) as management tools. Characteristics and imperatives include the preference of abundance over biomass or biovolume as the primary metric for the stock and the bipartite partition of the mortality rate into natural mortality and the additive portion contributed by disease that depends upon the distribution of the stock over the salinity gradient. Other contributing factors include female biases in natural mortality and fishery landings, application of a Ricker model for the broodstock-recruitment relationship, the influence of disease on the surplus production trajectory of the stock, and the importance of managing shell as well as live oysters. Reference points may be developed to manage the disease or the diseased stock. All reference points used in management at this writing are of the latter type. One is volume based; the remainder are abundance based. Constant-abundance reference points have received most attention. Reference points focused on msy have received little use. Constant-abundance reference points stabilize the stock at a known (usually the present) state. Constancy reference points can be applied to the management of the stock and also to the management of the shell resource critical to maintenance of reef habitat. The alternative msy approach is used to stabilize the stock at a state maximizing sustainable production. Though little used, consideration of the behavior of surplus production formulations suggests that msy-based reference points may be feasible and that this approach could then be used to identify management goals other than the present state.

Assessment of the stock status of small-scale and multi-gear fisheries resources in the tropical Eastern Pacific region

Small-scale multi-gear fisheries contribute half of global fisheries landings but are generally data-poor, hindering their assessment and management. Aiming to overcome various existing challenges, we used two complementary length-based approaches to assess the status of three main target species in the small-scale fisheries of Eastern Pacific countries: Spotted rose snapper Lutjanus guttatus, Pacific sierra Scomberomorus sierra, and Pacific bearded Brotula clarkae, using length-frequency catch data (LFCD) from the Colombian Pacific coast. Two data sources – official governmental data and community-based monitoring from a non-government organization – were used to estimate two sets of stock indicators: one based on the derivation of growth and mortality parameters from modal progression, catch curve analysis and a yield-per-recruit model using TropFishR; and the second based on the relative contribution of fish sizes with regard to proposed reference values for healthy stocks. Growth estimates differed between data sources and exhibited large confidence intervals, indicating an overall high uncertainty underlying the LFCD revealed through a novel bootstrapped approach. Estimated values of stock indicators, exploitation rate, fishing mortality and size-proportions converged in suggesting a state of heavy to over-exploitation for the three assessed species, although differences were observed among data sources that we attribute mainly to fisheries selectivity and sampling design. In order to improve future assessments of stocks in multi-gear and data-poor contexts, estimations of fleet-specific selectivity should be used to reconstruct LFCD prior to analyses. Additionally, sampling design should be based on fishing effort distribution among gears and areas and, when feasible, fishery-independent data on stock conditions should be included.

Influence of environmental and operational variables in commercial fishery landings: The case of pair trawlers in southeastern Brazil

Faced with the overexploitation reality of many of the world fish stocks and climate change, understanding the relationships between catches, fishing strategies and environmental conditions becomes crucial. In this context, this study aimed to describe the correlations between operational and environmental variables in landings of the main fish categories by pair trawl fisheries off the coast of southeastern Brazil. Catch composition varied greatly between 2003 and 2011. This change was mainly related to the shift of the fishing area to greater latitudes and variations in sea surface temperature and chlorophyll concentrations. The physical characteristics of the vessels and fishing gear did not change during the study period. Environmental variables most likely influence stock catchability, primarily by changing their distribution pattern, indicating a shift in ocean characteristics that will influence this dynamic. This draws attention to the need to maintain monitoring programs to apply adequate management measures for the protection of fish populations, consequently ensuring fishing activities in the area.

Productivity and coastal fisheries biomass yields of the northeast coastal waters of the Bay of Bengal Large Marine Ecosystem

Myanmar (Burma) is the second largest territory in Southeast Asia with a 2200 km coastline and continental shelf of 230,000 km2. The Myanmar exclusive economic zone (EEZ) occupies 80% of the northeast coastal waters of the Bay of Bengal Large Marine Ecosystem (BoBLME); a 300 km stretch of the Bangladesh coastline completes the area. Four decades ago a combination of extensive mangrove forests, large continental shelf and fertile deposits from the rivers systems discharging into the Bay from two mega deltas (Ganges–Brahmaputra–Meghna and the Ayeyarwady) generated high productivity and valuable coastal fisheries. In terms of productivity, the end of the dry season (April) is the most productive, with 2590 ± 1560 mg C m⁻2 day⁻¹ and high concentrations of chlorophyll a (3.14 ± 2.64 µg L⁻¹). In 2016, the Department of Fisheries (DoF Myanmar) reported marine fishery landings in Myanmar's waters of 2.9 million metric tons (mt), which would have accounted for 47% of the total BoBLME fish catch and 3% of global fisheries coming from 10% of the BoBLME maritime area of 6.2 million km2. Sequential fisheries assessments by Fridtjof Nansen Fisheries Research vessels over four decades have shown that in 2015 a combination of factors has led to reduced yields of valuable fish species by 80% while low value, fast-recruiting fish species have increased. A 2011 Transboundary Diagnostic Analysis (TDA), delivered by the Global Environment Facility (GEF) co-funded FAO implemented BoBLME eight-country project, describes the causes for this dramatic reduction in biomass yields. A Strategic Action Programme (SAP) designed to mitigate the problems was endorsed in 2016 and will be implemented in 2019. The area's coastal fishing fleets are 95% artisanal. There is a combined total of 442 species of fish, prawn, shrimp and lobster in the area. The transboundary hilsa (Tenualosa ilisha) fishery is the most economically important in both Bangladesh and Myanmar. WorldFish and the DoF (Bangladesh and Myanmar) are currently operating hilsa conservation projects in both countries with the International Institute for Environment and Development (IIED) and USAID funded Enhanced Coastal Fisheries in Bangladesh (ECOFISH) projects. A 2018 FAO-WorldFish fisher folk vulnerability and social protection study has demonstrated the precarious nature of coastal fishers.

Domestic landings and imports of seafood in emerging economies: The Brazilian sardines market

Seafood imports have increased strongly in emerging economies during the last decades. However, the impacts of increased imports on price determination process, local fishers' income and fish stocks have received limited attention. This paper presents a market integration and price transmission analysis for the Brazilian sardine market, comprising the fresh and canned sardines segments, to shed light on these issues. Imports currently supply about one-half the sardines in the Brazilian market, and even more when the domestic fishery landings are low. The results suggest not only a fully integrated market but also a complete price transmission in both sardine value chains. Hence, import competition with domestic fisheries limit price increases in the domestic fishery and reduce fishers' income and fishing effort. However, the canneries, consumers and fish stocks are better off.

The effect of regional sea surface temperature rise on fisheries along the Portuguese Iberian Atlantic coast

Abstract The environmental effects of climate change are expected to impact fisheries, and related economies, and represent a significant challenge for the development of government policy. The impact of ocean warming on fisheries yields is of particular concern. The effect of sea surface temperature (SST) on fisheries in three distinct biogeographic areas (north‐western, NW; south‐western, SW; and south, S) and different fleet sectors (trawl, seine, and multi‐gear) of the Portuguese coast was examined. The mean temperature of the catch (MTC) was applied to the official landings statistics to assess the effect of global warming on the exploited marine communities. MTC increased from 16.9, 16.7, and 17.4°C in 1989 to 17.9, 18.1, and 18.3°C in 2009, whereas the linear rate of MTC increase was 0.54, 0.49, and 0.70°C per decade in the NW, SW, and S regions, respectively. The increase of warmer species in fisheries landings is regional‐specific. The percentage increases in landings of warmer water species increased significantly from north to south: 5.1, 6.7, and 18% per decade in the NW, SW, and S, respectively. The results confirmed that ocean warming has affected the composition of fisheries landings (of warmer and colder species) in the three regions of the Portuguese coast. The results highlight the importance and urgency of considering the temperature‐induced shift in species distribution in fisheries management.

Possible Criterion to Estimate the Juvenile Reference Length of Common Sardine (Strangomera bentincki) off Central-Southern Chile

In the last century, the growing evidence that global fisheries are depleting natural resources much faster than they can recover has led to negative processes, like overfishing, being addressed with increasingly complex models and thus mitigating or regulating actions that aim to protect stocks. Said negative processes contain two components: (i) they can diminish the reproductive potential of fish stocks, called over exploitation by recruitment, and (ii) the effect of early capture prevents the full realization of the growth potential, called overfishing by growth. In this article, the structure of common sardine sizes is analyzed. Due to the precise moment in which pre-recruits are incorporated into the exploited phase of the stock is unknown, the estimation of a recruitment size is a hard problem. This problem is addressed by modeling the mean size via a stochastic process, applying models of structural change. A time series (2001–2015) was analyzed on a weekly time scale based on the size structure of the pelagic fishery landings in the central-southern zone of Chile (32∘10′–40∘14′ LS), from the V. to the XIV. Region. Specifically, the evolution of sizes according to macro-zones was studied for the conglomerates identified in two sub-zones, the V.–VIII. and IX.–XIV. Regions. In this context, the reference size for juveniles to cautiously allow the recruitment process of the common sardine from the central-southern zone of Chile was estimated, and the behavior of these sizes was spatially analyzed. Finally, a statistical inferential criterion was established that confirms the mean size of juveniles with a certain margin of error, which allows nonetheless later on to define a fraction that could be protected to avoid overfishing by growth.

Spatio-Temporal Variability of the Habitat Suitability Index for Chub Mackerel (Scomber Japonicus) in the East/Japan Sea and the South Sea of South Korea

The climate-induced decrease in fish catches in South Korea has been a big concern over the last decades. The increase in sea surface temperature (SST) due to climate change has led to not only a decline in fishery landings but also a shift in the fishing grounds of several fish species. The habitat suitability index (HSI), a reliable indicator of the capacity of a habitant to support selected species, has been widely used to detect and forecast fishing ground formation. In this study, the catch data of the chub mackerel and satellite-derived environmental factors were used to calculate the HSI for the chub mackerel in the South Sea, South Korea. More than 80% of the total catch was found in areas with an SST of 14.72–25.72 °C, chlorophyll-a of 0.30–0.92 mg m−3, and primary production of 523.7–806.46 mg C m−2 d−1. Based on these results, the estimated climatological monthly HSI from 2002 to 2016 clearly showed that the wintering ground of the chub mackerel generally formed in the South Sea of South Korea, coinciding with the catch distribution during the same period. This outcome implies that our estimated HSI can yield a reliable prediction of the fishing ground for the chub mackerel in the East/Japan Sea and South Sea of South Korea.

Linking zooplankton assemblages with oceanographic zones in an Atlantic coastal ecosystem

Shallow (5–35 m depth) coastal waters, with their proximity to human populations, are likely to experience greater changes to ecosystem structure and functions from climate change and human impacts than offshore waters. Concerns of declining fisheries landings and deteriorating habitat quality in Northumberland Strait led to an assessment by Fisheries and Oceans Canada of the state of the environment and biota including zooplankton during the summer. In this paper we describe spatial structure of zooplankton (three distinct assemblages) and determined that two oceanographic zones can explain the spatial variation. Using distance-based linear models, bottom water temperature and surface water salinity explained 16% to 25% of the variation in zooplankton composition for each year of the survey. We used retrospective analyses to estimate what the zooplankton assemblage may have resembled in the early 1990s from data of oceanographic conditions. Given the prediction of warming oceans by the Intergovernmental Panel on Climate Change, we provide a means of predicting zooplankton composition and their distribution, with implications for the planktivorous fishes that prey upon them.

Remotely Sensing the Biophysical Drivers of Sardinella aurita Variability in Ivorian Waters

The coastal regions of the Gulf of Guinea constitute one of the major marine ecosystems, producing essential living marine resources for the populations of Western Africa. In this region, the Ivorian continental shelf is under pressure from various anthropogenic sources, which have put the regional fish stocks, especially Sardinella aurita, the dominant pelagic species in Ivorian industrial fishery landings, under threat from overfishing. Here, we combine in situ observations of Sardinella aurita catch, temperature, and nutrient profiles, with remote-sensing ocean-color observations, and reanalysis data of wind and sea surface temperature, to investigate relationships between Sardinella aurita catch and oceanic primary producers (including biomass and phenology of phytoplankton), and between Sardinella aurita catch and environmental conditions (including upwelling index, and turbulent mixing). We show that variations in Sardinella aurita catch in the following year may be predicted, with a confidence of 78%, based on a bilinear model using only physical variables, and with a confidence of 40% when using only biological variables. However, the physics-based model alone is not sufficient to explain the mechanism driving the year-to-year variations in Sardinella aurita catch. Based on the analysis of the relationships between biological variables, we demonstrate that in the Ivorian continental shelf, during the study period 1998–2014, population dynamics of Sardinella aurita, and oceanic primary producers, may be controlled, mainly by top-down trophic interactions. Finally, based on the predictive models constructed here, we discuss how they can provide powerful tools to support evaluation and monitoring of fishing activity, which may help towards the development of a Fisheries Information and Management System.

Out of Sight, But Within Reach: A Global History of Bottom-Trawled Deep-Sea Fisheries From >400 m Depth

Deep-sea fish species are targeted globally by bottom trawling. The species captured are often characterized by longevity, low fecundity and slow growth making them vulnerable to overfishing. In addition, bottom trawling is known to remove vast amounts of non-target species, including habitat forming deep-sea corals and sponges. Therefore, bottom trawling poses a serious risk to deep-sea ecosystems, but the true extent of deep-sea fishery landings through history remains unknown. Here, we present catches for global bottom trawling fisheries between years 1950-2015. This study gives new insight into the history of bottom trawled deep-sea fisheries through its use of FAO capture data combined with reconstructed landings data provided by the Sea Around Us Project, which are the only records containing bycatches, discards and unreported landings for deep-sea species. We illustrate the trends and shifts of the fishing nations and discuss the life-history and catch patterns of the most prominent target species over this time period. Our results show that the landings from deep-sea fisheries are miniscule, contributing less than 0.5 % to global fisheries landings. The fisheries were also found to be overall under-reported by as much as 43 %, leading to the removal of an estimated 25 million tonnes of deep-sea fish. The highest catches were of Greenland halibut in the NE Atlantic, Longfin codling from the NW Pacific and Grenadiers and Orange roughy from the SW Pacific. The results also show a diversification through the years in the species caught and reported. This historical perspective reveals that the extent and amount of deep-sea fish removed from the deep ocean exceeds previous estimates. This has significant implications for management, conservation and policy, as the economic importance of global bottom trawling is trivial, but the environmental damage imposed by this practice, is not.

<b>Jatuarana fishing dynamics <i>Brycon amazonicus</i> (Spix & Agassiz, 1829) of the upper and middle Madeira River Basin

The jatuarana ( Brycon amazonicus ), is an important species for the Madeira River commercial fisheries. The paper aims to characterize the jatuarana fishing dynamics in the middle Madeira River and test whether there are differences dowstreams and upstreams the Teotonio waterfall. Commercial fisheries landings were monitored daily at 15 ports or riverine communities along that stretch, using semi-structured interviews with fishermen. With data from the fishing monitoring program of UHEs Santo Antonio and Jirau we analysed: the yield, catch per unit effort (CPUE), length structure, locations and fishing gear used, between 2009 to 2011.The fishing yield of this species was temporaly analyzed with data from the Fishermen Colony of Porto Velho city (Rondonia state, Brazil), between 1990 to 2012. The yield and the CPUE showed significant differences by area and locations and the capture of the species was carried out primarily in the channel river and banks river through gillnets. In addition, the samples collected in the upstream area have higher distribution and modal lengths than from those collected downstream. These results suggest that the areas require distinct management measures.

Using remote sensing indicators to investigate the association of landings with fronts: Application to the Alboran Sea (western Mediterranean Sea)

AbstractThis study examined links between the variability of coastal front features and composition of fishery landings. Satellite‐derived sea surface temperature data allowed the detection of thermal fronts and calculation of front metrics that account for gradient, persistency, and vicinity. Landings data were clustered by functional group (according to habitat use, size, morphology), and trophic level (TL). Three independent time series analyses, based on two different classes of statistical methodologies, were carried out: (i) correlation analysis performed on species aggregated by functional groups, and (ii) compositional analysis performed on the top five species landed and on species aggregated by trophic level. Analyses were carried out for the Moroccan coast of the Alboran Sea (western Mediterranean Sea). Results of the proposed type of application were discussed with respect to their potential for improving scientific knowledge and management of fisheries in data‐poor areas. Pelagic landings were associated with front indicators in two‐thirds of tested cases. The results demonstrated a markedly different association between landings and front features in the Nador fishing zone, relative to M'diq and Al Hoceima. Improved performance of the front gradient and persistence indicator was detected, with respect to the front gradient only for flatfish and demersal landings. Compositional data regression outlined a different role for Sardina pilchardus and Trachurus trachurus in the Al Hoceima and M'diq landings, and in the latter case the dominance of these two species in the landings seemed to respond to the front density indicator. A decreasing trend in TL > 3.5 landings was detected with increasing front distance.

A socio-ecological approach to the declining Catalan clam fisheries

The world demand for marine bivalves continuously increased from 1980 to 2014. Their fisheries landings in the Mediterranean Sea also increased, until they began to drop in the last decade. This trend was particularly intense in the western Mediterranean Sea, where landings dropped from 4046 t (1996) to 425 t (2012). Since then, they have never recovered. We examined the status of the main commercial clam species in Catalonia (NW Mediterranean) one of the main productive areas of the western Mediterranean Sea, and analyzed the social and ecological context of the different small scale clam fisheries as an example of the Mediterranean as a whole to detect the possible causes of this negative trend. Our results reveal the critical status of all clam fisheries along the entire coast, where most clam stocks are currently collapsed or close to collapse. This trend mirrors the evolution of bivalve fisheries in the western Mediterranean. Many management failures and factors inhibiting the sustainability of clam fisheries over time were detected (i.e. the nearly absence of resource monitoring or control of rules enforcement; lack of conflict resolution mechanisms among fishermen and other coastal users; the incongruence between appropriation and provision regulations, and deficient nested enterprises), suggesting that inadequate and incongruent management is largely to blame for the precarious present situation. However, our results also suggest that undetermined additional factors (e.g. pathologies, pollution, climate change etc.) have also affected what were already highly stressed populations.

Winners and Losers in Area-Based Management of a Small-Scale Fishery in the Colombian Pacific

The Pacific coast of Colombia has some of the most extensive mangrove forests in South America. As an isolated region and one of the country’s poorest, coastal communities rely on fishing as a main source of animal protein and income. In an attempt to reverse declining trends of fisheries resources, in 2008, an Exclusive Zone of Artisanal Fishing closed to industrial fishing, was established by stakeholders in the Northern Choco region. Here we present a case study to investigate the effects of this area-based management on fisheries productivity and catch composition. Fishery landings data from 2010 to 2013 are compared to those of a neighbouring region with no fisheries management. Catch per unit effort, mean weight landed, and number of landed individuals were calculated for mangrove and non-mangrove associated species by boat type and fishing gear. A set of mixed effects models were used to unpack the effects of multiple factors and their interactions on response variables. Results show that across fishing gears and time, mean catch per unit effort increased by 50% in the Exclusive Zone of Artisanal Fishing within 3 years. Fisheries here focused on offshore resources with 61% more fishing trips associated with motorized boats than in the unmanaged region, where fishing was predominantly in mangroves and close to the coast. This suggests that fisheries management, may have played a role in reducing pressure on mangrove resources. However, area-based management may have also driven the displacement of fishing effort by excluding industrial trawlers, which then concentrated their activity in neighbouring areas.