Small Pelagic Fish Stocks Research Articles

Influence of migrant Western Regional shark fishers on shark fishing practices along the eastern coastline of Ghana

Sharks have formed an integral part of Ghana’s fisheries for many years, although in many areas outside the Western Region, they are often captured as bycatch. The shark fishery in the Dangme communities along the eastern coastline of Ghana has, however, over the last decade, acquired a commercial character that is believed to have been influenced by migrant fishers from the Western Region. This study thus sought to characterise the influence of the migrant fishers in the development of the thriving shark fishery in Dangme communities. Data collection was through key informant interviews, questionnaire administration to 180 randomly selected native and migrant fishers from the selected communities, and observations of fishing practices. Until the mid-2000 s, only the migrant fishers carried out targeted shark fishing along the Dangme coastline. Presently, however, a significant number of native fishers have redirected their fishing efforts towards shark fishing in the face of dwindling catches from the small pelagic fisheries, which were the primary target of the fisheries. Accounts 75 % of native fishers indicated that the declines in small pelagic fish stocks coupled with the influence of the migrant shark fishers have acted synergistically to influence the shark fisheries dynamics along the Dangme coastline. Despite the average ages of the native and migrant fishers being fairly the same (∼36 years), the migrants possessed a more profound understanding of the marine ecosystem where they operated based on historical antecedents and their longer interactions with the shark fishing zones. Presently, this new fishery, like shark fishing in other shark fishing hotspots in Ghana, is unregulated, but it will be imperative for national fisheries authorities to implement some management measures to reduce fishing pressure on the most vulnerable species.

A delay‐differential model for representing small pelagic fish stock dynamics and its application for assessing alternative management strategies under environmental uncertainty

AbstractWe present a novel adaptation of the classic discrete delay‐difference model, a continuous delay‐differential model (cDDM), which can adequately represent population dynamics of stocks that turn over rapidly and continuously over time (e.g., small pelagic fish, small tunas, and shrimps). We used the Northern‐Central Peruvian anchoveta stock (Engraulis ringens, Engraulidae) as a case study for implementing the cDDM and conducted a management strategy evaluation (MSE) through stochastic optimization in policy space (SOPS). Our results showed that cDDM integrated with SOPS efficiently searches optimum and near‐optimum harvest control rules (HCR) and is an alternative to pre‐setting arbitrary HCRs as in traditional MSE. The cDDM showed comparable stock biomass and recruitment estimate reconstructions to more complex stock assessment models described for anchoveta. We concluded that the anchoveta stock is sustainably managed and is an example of adaptive fisheries management under high ocean‐climate variability and uncertainty. Contrary to fishery textbooks, the anchoveta's collapse was not entirely due to the 1972 El Niño (EN) but a recruitment failure preceding EN. Our reconstructions revealed that low recruitment (or recruitment failure) could still occur at high stock biomass. Anchoveta's stock biomass is larger than pre‐collapse, likely due to favourable environmental conditions (a cooling trend) and management, despite more frequent and stronger EN events. SOPS quickly revealed that harvest strategies with large base biomass (>5 mmt) lead to higher interannual stock variability and would not produce substantial increases in long‐term yield. Alternative HCRs with lower base biomass, while adjusting for productivity regimes, have similar long‐term yields without affecting the long‐term average stock.

MICROPLASTIC THREATS IN THE CULTURED OF SANDFISH (Holothuria scabra): A CASE STUDY OF PASAR ISLAND, BANDAR LAMPUNG

Small pelagic fish stocks are the highest and most caught fish stocks for Indonesian consumption. Pelagic fish generally live in shallow water and form schools that act as intermediate consumers in the food chain (between producers and larger fish), thus requiring protective measures. This study aims to determine the growth rate and utilization of pelagic fish in Indramayu Regency, West Java. Fish sampling uses a literature review of data information from fishermen and other economic actors who utilize the pelagic fish ecosystem. Pepetek fish are expected to die earlier than tuna because pepetek fish reach asymptotic body length earlier than tuna with low growth factors in the results of studies with high growth rates. Pepetek, kurisi, kuniran, cob and tembang have very low exploitation rates below 50%. For mackerel, the recovery rate is 70.85%. This means that the average catch that occurs in Indramayu waters does not exceed the optimal limit of 50% so that there is no overfishing.

Основные направления научного рыбохозяйственного сотрудничества России со странами Северо-Западной Африки

Coastal African countries, primarily Morocco and Mauritania, are partners of the Russian Federation in the field of marine fisheries and scientific cooperation plays a key role in this collaboration. It has more than half a century of history. Cooperation between Russian and African scientists makes it possible to improve the quality of monitoring of small pelagic fish stocks’ condition in the Central-Eastern Atlantic area and to manage them more reliably, including within the framework of annual meetings of the FAO Working Group on the Assessment of Small Pelagic Fish Stocks in North-West Africa. This paper presents a brief overview of scientific fishing and economic cooperation between Russia and the countries of North-West Africa.

Recent trends in abundance and fishing pressure of agency‐assessed small pelagic fish stocks

AbstractSmall pelagic fishes are used for human consumption, fishmeal and fish oil. They constitute 25% of global fish catch and have been of considerable conservation concern because of their intermediate position in aquatic food webs, often being a dominant dietary component of marine predators. This paper provides an overview of trends in abundance and fishing pressure on small pelagic fish stocks from single‐species scientific assessments that constitute 60% of global small pelagic catch. While most individual stocks have exhibited wide variability in abundance (typical of small pelagics compared with other fish taxa), across stocks there has been remarkable stability in average fishing pressure and biomass since 1970. On average, since 1970, the biomass of assessed small pelagic stocks is estimated to have been slightly above the biomass that would produce maximum sustainable yield, but estimation of this quantity for highly fluctuating stocks is quite uncertain. There were significant differences among assessed regions, with the Mediterranean and Black Sea of greatest concern for high and growing fishing pressure. The 40% of global small pelagic fish catch not covered by single‐species quantitative stock assessments since 1970 comes largely from Asia, where catches have continued to increase. At regional levels, the average abundance of assessed small pelagic fish is largely unrelated to average fishing pressure, which we argue results both from the portfolio effect, where numerous stocks fluctuate with little correlation in abundance, and from the short life span of small pelagics coupled with recruitment largely independent of spawning abundance.

Assessment of small pelagic fish stocks in Ghanaian and adjacent waters

a) Five stocks of small pelagic fish important to Ghana are assessed for the period 1990-2017. These are based on the stock area as used by FAO that also includes catches from Cote d’Ivoire, Togo and Benin. The stocks assessed include anchovy (Engraulis encrasicolus), round sardinella (Sardinella aurita), flat sardinella (Sardinella maderensis), bonga shad (Ethmalosa fimbriata) and Cunene horse mackerel (Trachurus trecae). b) Ghana accounts for the largest proportion of the total catches for all stocks from the four countries in the assessment unit. Total catches are variable and show some long term decline for four of the five stocks. Catches of horse mackerel have increased. c) Fishing effort data are available for 6 fleets. Effort trends are highly variable but Ghanaian fleets, that account for most of the catch show a marked increase. d) Catch per unit effort data (cpue) suggest that all stocks, except horse mackerel have declined from the 1990 level but may have stabilised or increased slightly in recent years. However, the trends may be over-optimistic as the effort data are not corrected for increases in fishing power. Horse mackerel cpue shows no long term trend. e) A surplus production model is used to assess the stocks using catch and effort data by fleet. The model also accounts for increasing fishing power over time, missing catch data as well as observation errors in the catch and effort data. f) Four of the five stocks show similar downward trends in stock biomass and increasing fishing mortality. They appear to be fished above FMSY and the current biomass is below BMSY. The estimates of FMSY are uncertain but the estimated stock status relative to MSY is robust to different modelling assumptions. The horse mackerel stock shows no clear trend in biomass and while is appears to be fished above FMSY, the stock status is highly uncertain. g) In all five stocks Ghanaian fleets dominate the fishing mortality with the artisanal fleet having a large impact. Cote d’Ivoire makes a large contribution to fishing mortality on sardinella and horse mackerel. Togo makes a significant contribution to anchovy mortality h) Estimates of the rate of increase in fishing power vary between fleets and species. Most notable is the above average increase in fishing power by the Togo artisanal fleet for anchovy and round sardinella, and the Benin artisanal fleet for most stocks. i) Equilibrium analyses suggest that all five stocks are at high risk of stock collapse at current (2017) rates of fishing, though there is large uncertainty in the case of horse mackerel. Much of the catch appears to be dependent on in year production (recruitment and growth). j) Despite uncertainty in the estimates of BMSY and FMSY, the model described in the analysis provides the basis for a multi-fleet, fishery model that can be used to investigate management scenarios and economic impacts.

A Return to the Ghanaian Cultural Values of Closed Fishing Season in Ghana’s Artisanal Marine Fishing: An Essential Means of Restoring Small Pelagic Fish Stocks

Abstract Closed fishing season for artisanal and inshore fishing is an effective management measure for restoring the fish stock. The study aimed at assessing the impacts of the closed fishing season observed in the Sekondi harbour in Ghana. The findings revealed that the one month closure period was too short and/or lack of strict supervision to realize any significant change in fish population and sizes. A more transparent discussion on the period for the closure, longer closure period up to three months as well as provision of alternative sources of livelihood were suggested to ensure more cooperation from the fisher folks.

Quality control of small pelagic fish stocks in distribution line in Ambon and Kei Kecil, Maluku

Fish is very perishable, soon after caught and death, deterioration took place quickly especially in a high-temperature environment. Quality control is a necessity to keep the freshness of fish and the prime nutritional quality. In this study interview and observation were done on the focus group to investigate quality control activities carried out by the artisanal fisher community. In many places in Maluku, small pelagic fish caught by using purse seine net. The fishing ground is relatively close to the landing site at the coastal area and landed in 1-2 hours after death. Shortly after landed ice treating is applied on the fishes with the ratio of ice to fish roughly 1:2 and also a small amount of clean sea water added onto the fish-ice mixture in order to chilling fish and keep it fresh. Most fish are transported to the central market in town by using cars which takes one to two hours, and the rest taken by the small retailers and distribute to the closest markets in the village. If lots of fish harvested, some retailers will sell it on foot from house to house. The small-scale fishermen and retailers know very well the necessity of maintaining the freshness of fish, so it will be in good quality when delivered the consumer hands and the high price.

Power and access issues in Ghana's coastal fisheries: A political ecology of a closing commodity frontier

Primarily applied to land-based resources, academics have utilised the concept of commodity frontiers to understand the expansionary nature of capitalism, and the ways that existing hegemonies and systems of control and access of resources are challenged and altered. Following recent calls to expand this concept to marine spaces, this paper has used political ecology and in particular its focus on power and access to explore how capitalist expansion has impacted the means and methods of access to key resources in a small-scale marine fishing community in Ghana. The findings of the paper are based upon an eight-month field visit to Aboadze in the Western Region of Ghana, a traditional fishing community that is considered a ‘closing’ frontier, on account of recent research that suggests the small-pelagic fish stocks will collapse within a decade. The findings of the paper show that accessing fish and other necessary resources such as gear and capital has become increasingly difficult as stocks continue to dwindle, and those living in the case study community have to resort to unsustainable fishing methods in order to survive. The paper also finds that the vulnerability caused by decades of overfishing by foreign trawlers is felt disproportionately by certain members of the community, compounding existing vulnerabilities that arise through gender and class.

Profit and equity trade‐offs in the management of small pelagic fisheries: the case of the Japanese sardine fishery*

The management of small pelagic fisheries is difficult due to environmental regime changes that generate multi‐decadal cyclic fluctuations in stock abundance. Lagged management responses to environmental factors can amplify the effects of fishing and may even result in stock collapse. In this paper, we develop an age‐structured bioeconomic model to explore the effectiveness of alternative management approaches for cyclically fluctuating small pelagic fish stocks. The fishery outcomes are evaluated against the overall profit of the fishery and the intertemporal distribution of fishing profits. The model is parameterised for the Japanese sardine fishery, once the largest fishery in Japan, which has experienced a prolonged period of stock collapse over the last 100 years. The results show that the duration of fishery collapse is mostly determined by the extent of cyclic fluctuations in the recruitment of immature sardines, but the effects of the fluctuations on the fishery are heightened by the cumulative impact of fishing. We further show that restricting fishing reduces the fishery’s overall profits, but smooths the intertemporal distribution of profits, resulting in greater intergenerational equity. This income smoothing effect is particularly pronounced when the stock exhibits high levels of cyclic fluctuations.

Unclear associations between small pelagic fish and jellyfish in several major marine ecosystems

During the last 20 years, a series of studies has suggested trends of increasing jellyfish (Cnidaria and Ctenophora) biomass in several major ecosystems worldwide. Some of these systems have been heavily fished, causing a decline among their historically dominant small pelagic fish stocks, or have experienced environmental shifts favouring jellyfish proliferation. Apparent reduction in fish abundance alongside increasing jellyfish abundance has led to hypotheses suggesting that jellyfish in these areas could be replacing small planktivorous fish through resource competition and/or through predation on early life stages of fish. In this study, we test these hypotheses using extended and published data of jellyfish, small pelagic fish and crustacean zooplankton biomass from four major ecosystems within the period of 1960 to 2014: the Southeastern Bering Sea, the Black Sea, the Northern California Current and the Northern Benguela. Except for a negative association between jellyfish and crustacean zooplankton in the Black Sea, we found no evidence of jellyfish biomass being related to the biomass of small pelagic fish nor to a common crustacean zooplankton resource. Calculations of the energy requirements of small pelagic fish and jellyfish stocks in the most recent years suggest that fish predation on crustacean zooplankton is 2–30 times higher than jellyfish predation, depending on ecosystem. However, compared with available historical data in the Southeastern Bering Sea and the Black Sea, it is evident that jellyfish have increased their share of the common resource, and that jellyfish can account for up to 30% of the combined fish-jellyfish energy consumption. We conclude that the best available time-series data do not suggest that jellyfish are outcompeting, or have replaced, small pelagic fish on a regional scale in any of the four investigated ecosystems. However, further clarification of the role of jellyfish requires higher-resolution spatial, temporal and taxonomic sampling of the pelagic community.

More than fifteen years of collaboration on the assessment of small pelagic fish off Northwest Africa: Lessons learned and future perspectives

Ensuring the sustainable use of the small pelagic fish stocks and the sustainable management of the fisheries exploiting them is a significant challenge faced by countries in Northwest Africa. Small pelagic fish constitute the bulk of the landings in this region, with annual catches of the main species ranging from approximately 1.7 to 2.5 million tonnes over the last few decades. Many of the main pelagic stocks are distributed across the 200 nautical-mile boundaries of the sub-region, and are shared bilaterally or sub-regionally among countries of Western Africa. These resources, which migrate along the Northwest African coast, are exploited by local fleets of both the artisanal and industrial sectors, as well as distant water fishing vessels from Europe, Asia, and Central America. The transboundary nature of these fish stocks calls for joint action with respect to their monitoring and management. In 2001, the Food and Agriculture Organization of the United Nations created a permanent working group on the assessment of small pelagic fish off Northwest Africa, which today reports to the Fishery Committee for the Eastern Central Atlantic. As a result of this Working Group's efforts, more consistent series of catch and effort and annual abundance indices of the main small pelagic fish species are now available, and significant improvements in sampling intensity have been achieved. Furthermore, consolidated annual advice is provided at a regional scale on the state of these resources that complements the national assessment and management advice systems. This paper provides some reflections on the contributions of the Working Group to science-based fisheries management and possible future actions that could further strengthen the collaborative momentum gained through this type of regional collaboration.

The influence of environmental factors and hydrodynamics on sardine (Sardina pilchardus, Walbaum 1792) abundance in the southern Alboran Sea

Abstract The study of environmental variables and their influence on the small pelagic fish stocks of the Alboran Sea (Western Mediterranean) is asymmetrical, with studies focused on the southern coast being scarce compared with those looking at the northern margin. In this work, time series of sardine landings from the Moroccan coast of the Alboran Sea from 1981 to 2016 were analyzed together with environmental variables such as Sea Surface Temperature (SST), Sea Surface Salinity (SSS), Surface Chlorophyll-a concentrations (Chl-a), and the velocity of the Atlantic Jet (AJ) flowing into the Mediterranean Sea through the Strait of Gibraltar. Annual sardine catches decreased from 1981 to 2016 at a rate of −258 t/year. At the same time, the SST and SSS increased at rates of 0.03 °C/year and 0.004 ups/year, respectively, very likely as a result of climate change. Linear models reflect a negative relationship between sardine landings and SST and SSS, indicating that the long-term temperature and salinity changes in the Mediterranean could have a negative impact on sardine abundance. At an inter-annual time scale, chlorophyll concentrations seem to be positively related to sardine abundances. A decrease in the kinetic energy of the AJ is also inferred from the cross-strait sea level difference (SLD). This variable has an important influence (positive correlation) on sardine landings, both in the long term and at the inter-annual time scale, with higher sardine abundances associated to higher SLD. This work shows that environmental variables such as SLD, SST, SSS, and Chl-a are the main driving factors for the variability of sardine landings in the southern Alboran Sea.

Small pelagic fish dynamics: A review of mechanisms in the Gulf of Lions

Around 2008, an ecosystem shift occurred in the Gulf of Lions, highlighted by considerable changes in biomass and fish mean weight of its two main small pelagic fish stocks (European anchovy, Engraulis encrasicolus; European sardine, Sardina pilchardus). Surprisingly these changes did not appear to be mediated by a decrease in fish recruitment rates (which remained high) or by a high fishing pressure (exploitation rates being extremely low). Here, we review the current knowledge on the population's dynamics and its potential causes. We used an integrative ecosystem approach exploring alternative hypotheses, ranging from bottom-up to top-down control, not forgetting epizootic diseases. First, the study of multiple population characteristics highlighted a decrease in body condition for both species as well as an important decrease in size resulting from both a slower growth and a progressive disappearance of older sardines. Interestingly, older sardines were more affected by the decrease in condition than younger ones, another sign of an unbalanced population structure. While top-down control by bluefin tuna or dolphins, emigration and disease were mostly discarded as important drivers, bottom-up control mediated by potential changes in the plankton community appeared to play an important role via a decrease in fish energy income and hence growth, condition and size. Isotopic and stomach content analyses indicated a dietary shift pre- and post-2008 and modeled mesozooplankton abundance was directly linked to fish condition. Despite low energy reserves from 2008 onwards, sardines and anchovies maintained if not increased their reproductive investment, likely altering the life-history trade-off between reproduction and survival and resulting in higher natural mortality. The current worrying situation might thus have resulted from changes in plankton availability/diversity, which remains to be thoroughly investigated together with fish phenotypic plasticity.

Effects of changing nutrient inputs on the ratio of small pelagic fish stock and phytoplankton biomass in the Black Sea

Significant increases in nitrogen and phosphorus inputs to the Black Sea in the second half of the 20th century caused eutrophication and drastically decreasing Si:N and Si:P ratios. Combined with climate change, overfishing of top predators and a huge outbreak of the non-indigenous ctenophore Mnemiopsis, the pelagic food web was strongly modified and its efficiency for channeling primary production to higher trophic levels substantially reduced. We used the ratio between small pelagic fish stock and phytoplankton biomass on the Danube shelf and in the open Black Sea to investigate long-term changes in food web functioning. The ratio had 1) highest values for the pre-eutrophication period when diatoms and copepods dominated the pelagic food web (‘muscle food chain’), 2) decreased during the eutrophication period with stronger prevalence of autotrophic pico- and nanophytoplankton, bacteria, heterotrophic nanoflagellates, microzooplankton, Noctiluca and jellyfish (‘jelly food chain’ with increased importance of the microbial loop), 3) lowest values during the ecological crisis (1989–1992), when small pelagic fish stocks collapsed, and 4) increased after 1993, indicating that the ecosystem went out of the crisis and exhibited a trend of recovery. However, in the last period (1993–2008) the ratio remained close to values observed in the middle eutrophication phase, suggesting that the ecosystem was far from fully recovered. Since early 2000s, fluctuating pelagic fish stocks, with a tendency to decreasing fish landing again, have been observed in the Black Sea. Additionally, the quality of food for the small pelagic fish has deteriorated due to warming trends and the legacy of eutrophication, giving support for the ‘jelly food chain’, exhibiting low energy transfer and prevalence of organisms with high respiration rate and low nutritional value.

Variations in productivity of the Canary Current Large Marine Ecosystem and their effects on small pelagic fish stocks

The Canary Current Large Marine Ecosystem (CCLME) is a Global Environmental Facility (GEF) Project, situated in the Atlantic Ocean on the North West coast of Africa. It has seven countries with a population estimate of 64.5 million and a coastline of more than 5400km with a sea area of 2 million km2 within their Exclusive Economic Zones (EEZ). This area is one of the richest productive marine ecosystems in the world and its coastal and oceanic waters are rich in biodiversity and hosts approximately 12,500 species dominated by crustaceans, mollusks and fish. The total annual value of the ecosystem services provided by the CCLME is estimated to be around U$11.7 billion.The interaction between the CCLME and seasonal change in the ocean-atmospheric dynamics drives the productivity which has a mean annual value for chlorophyll of 1.31mgchla/m3 and 372gCm2yr−1 for primary productivity, based on SeaWiFS satellite data. This productivity supports abundant fish stocks with catches up to 3 million tonnes per annum being landed from the region. Fish population are dominated by the small pelagics especially sardine (Sardina pilchardus), sardinellas (Sardinella sp.) and horse mackerels (Trachurus sp).Satellite derived measurements from 1997 to 2012 reveal a downward trend in primary production and this decline is accompanied by a net warming of the system and a decrease in the upwelling. The declining trends and variability in biomass of some main target commercial fish species observed during these last year was accompanied by significant fishing pressure together with fluctuations in environmental factors which may have been a key drivers of change. Future studies on the ocean dynamics of the CCLME system, its impact on resources, environmental interactions and climate change will have to be closely monitored to ensure effective transboundary management.

POTENTIAL PRODUCTION OF THE FIVE PREDOMINANT SMALL PELAGIC FISH SPECIES GROUPS IN THE JAVA SEA

The Java Sea is one of the important fishing areas for small pelagic fishery in Indonesia. The production of the fishery was dominated by five fish species groups. To support the management of that fishery, an assessment of the stock of the five predominant small pelagic fish species groups was conducted. Based on the result of analysis, the maximum sustainable yield (MSY) of the stock of five predominant small pelagic fish species was about 244.6 thousand tons. Meanwhile, the MSY of the stock of the whole exploitable small pelagic fish species was about 315.5 thousand tons. The optimum fishing effort (EMSY) was 1032 units. The total fishing effort was higher than EMSY and the fish stock was likely over-exploited since 2000. To ensure the optimal fish production of the small pelagic fish stock in the Java Sea, it is necessary to recover fish stock by controlling fishing effort to EMSY. The time which it takes for the fish stock to recover was about two years when fishing effort was reduced from its level in 2009 to EMSY.

Irreplaceable area extends marine conservation hotspot off Tunisia: insights from GPS-tracking Scopoli’s shearwaters from the largest seabird colony in the Mediterranean

Recent meta-analyses identified conservation hotpots at the scale of the Mediterranean, yet those may be crude by lack of detailed information about the spatial ecology of the species involved. Here, we identify an irreplaceable marine area for >95 % of the world population of the Scopoli’s shearwater (Calonectris diomedea), which is endemic to the Mediterranean and breeds on the island of Zembra off Tunis. To this end, we studied the three-dimensional at-sea movements of 50 breeding adults (over a total of 94 foraging trips) in 2012 and 2013, using GPS and temperature–depth recorders. Feathers were also collected on all birds to investigate their trophic status. Despite Zembra being the largest seabird colony in the Mediterranean (141,000 pairs), the per capita home-range of Scopoli’s shearwaters foraging from this colony was not larger than that of birds from much smaller colonies, indicating highly beneficial feeding grounds in the Gulf of Tunis and off Cap Bon. Considering depleted Mediterranean small pelagic fish stocks, supposed to be Scopoli’s shearwater prey base, we therefore speculate that birds may now also largely feed on zooplankton, something which is supported by our stable isotopic analyses. Crucially, shearwater at-sea feeding and resting areas showed very little overlap with a conservation hotspot recently defined on the western side of the Gulf of Tunis using meta-analyses of species distributions relative to anthropogenic threats. We therefore propose a major extension to this conservation hotspot. Our study stresses the importance of detailed biotelemetry studies of marine megafauna movement ecology for refining large-scale conservation schemes such as marine protected area networks.

EXPLOITATION AND CPUE TREND OF THE SMALL PELAGIC FISHERIES IN THE SULAWESI SEA, INDONESIA

One of the expected benefits of the Sulu-Celebes Sea Project during its implementation is to have increased fish stocks at demonstration sites, as indicated by the Catch per Unit of Effort (CPUE). Analysis of catch and effort data of the small pelagic fisheries by using the surplus yield model was done to obtain information on the likely trend of CPUE for the last ten years. By using the pajeko as the standardized fishing gear the trend of CPUE has been calculated. Between 2000-2005, the trend of production (catch), effort and CPUE followed the general pattern of the exploited fisheries that already fully exploited, where the increasing trend of effort was not followed by the increasing catch. On the other hand, the trend of CPUE is decreased. In the following years, the trend of both catch and CPUE do not follow the general pattern of the exploited fisheries. The trend of catch, effort and CPUE has likely been stable, indicating that the fishery in this period has been leveled-off. The status of exploitation of the small pelagic fish resources in the Indonesian Sulawesi Sea is demermined by the MSY level that has likely been surpassed during the period 2003-2004. Therefore with the increasing effort in the following year the trend of catch was relatively stable. It is likely that the small pelagic fish stock in the Indonesian Sulawesi Sea might be ‘fully exploited’.

Interactions between aquaculture and fisheries

Aquaculture is increasingly interacting with fisheries from a socio-economic perspective at the level of the global food market. In addition, since 36% of landings from fisheries are used for the production of fishmeal and fish oil, which are essential feed elements for many aquaculture species, another source of interaction is at the level of the aqua feed market. The relevance of the interactions between the two sectors is becoming more evident as the process of transition from fishing to farming has reached a pivotal point, with almost 50% of the fish food supply now coming from aquaculture. The analyses on aquaculture and fisheries interactions often result in diverging views. This paper reviews the main positions in the recent scientific literature, structuring the discussion along the following themes: food market interactions; comparison of resources use by means of Life Cycle Assessment; use of fishmeal and fish oil and aqua feed markets; impacts on small pelagic fish stocks; food security; technical substitution of fishmeal and fish oil with alternative ingredients. The review is not aimed at taking a definitive position in respect of these complex issues but rather at summarising the different scientific contributions and indicating possible areas for further research. Research on fisheries and aquaculture interactions is considered beneficial in terms of policy support especially now that the reform of European Common Fishery Policy is assigning greater relevance to the growth of aquaculture and to its role in terms of socio-economic development for coastal and rural communities. In a more global perspective, the understanding of interactions between aquaculture and fisheries is important to evaluate the respective contributions to food security goals and the implications in terms of environmental sustainability and resource use efficiency.