CGIAR Research Program on Aquatic Agricultural Systems (2012) CGIAR Research Program on Aquatic Agricultural Systems. Penang, Malaysia. AAS-2012-24 | The Adivasi Fisheries Project (AFP) set out in 2007 to help Adivasis in the north and northwest of Bangladesh find new and more sustainable livelihoods. It is based on 2 decades of WorldFish research in Bangladesh on aquaculture techniques for smallholders and community fisheries management and targeted disadvantaged rural minorities called Adivasi. The enduring effects of the Adivasi Fisheries Project (AFP) are still being felt, three years after the project ended. During the project, fish production increased five-fold, fish consumption nearly quadrupled and the average household income for members of this vulnerable population improved significantly, far outstripping project expectations. Many of the nearly 3600 households that participated in the project are still using the aquaculture techniques that they learned, and others in the community have also adopted the practices

As tools within ecosystem-based fisheries management (EBFM), a wide range of Ecosystem Models (EMs) have been designed to represent ecosystem complexity, but it is not always clear how the outputs of these models can be applied. We address this debate in a literature review to illustrate how a better understanding of ecosystem modeling within the EBFM framework could facilitate the use of EMs in the decision-making process. We classify EMs according to their complexity, and qualitatively evaluate their level of success with regard to five general goals of EBFM. In principle, no single EM is found to successfully accomplish all the EBFM goals. Therefore, we suggest that the way in which ecosystem modeling can effectively contribute to EBFM is through a structured modeling process, which should be pursued according to the context of each specific area. Within this planning strategy a range of Ems should be considered, from rather simple ones with few parameters, whose outputs are scientifically robust but possibly of limited use within the EBFM, to those which include a large number of ecosystem elements yet at the expense of increased uncertainty. If multiple EMs, despite their different assumptions, leads to consistent and converging results then robust management decisions will be supported. The present paper appears particularly useful to anyone confronted with the selection of modeling tools for the implementation of fisheries management strategies considering the particular situation of the fishery.

Identification of population-specific run timing is an important component of salmonid fisheries management and was a major focus of our study. Population structure of steelhead Oncorhynchus mykiss was examined in the Skeena River of northern British Columbia. Variation at 14 microsatellites was surveyed in 3,062 steelhead sampled from 17 populations in the drainage. During 1998–2010, 6,691 individuals were sampled in a lower river test fishery to obtain information on relative abundance and time of arrival of specific populations near the river mouth. The genetic differentiation index F ST calculated over all populations and loci was 0.021; individual locus values ranged from 0.017 to 0.045. Differentiation in steelhead allele frequencies among populations was approximately 14 times the differentiation observed among years within populations. A regional structuring of populations was the general pattern observed, with steelhead populations from the upper portion of the drainage clustering together in 87% of dendrograms evaluated and those in the lower portion of the drainage clustering together in 100% of dendrograms. The 17 populations sampled were arranged in nine reporting groups for genetic stock identification applications. The estimated stock composition of a simulated known-origin mixture was within 2% of the correct estimate for seven of the nine reporting groups present in the mixture. The stock composition of an actual known-origin sample was estimated within 2% of the correct estimate for eight of the nine reporting groups present. Application to actual samples from the test fishery indicated that upper drainage populations generally migrated through the lower river earlier than other populations, whereas lower river populations typically migrated later. Genetic mixed-stock analysis can assist managers in regulating fisheries to maintain productivity of Skeena River steelhead.

The application of the “ecosystem approach” to fisheries management demands knowledge of the patterns of habitat use of target species but in the case of seamounts, this information is still very limited or, for most species, simply unavailable. Novel approaches, such as the use of acoustic biotelemetry in deep sea environments can potentially elucidate the spatial behaviour of seamount associated fishes. We tested the use of passive acoustic telemetry to study the residency of sub-adult and adult blackspot seabream (Pagellus bogaraveo) at the Condor seamount, Azores, mid-north Atlantic. Twenty‐eight fish tagged with acoustic transmitters were monitored by two receivers moored at the summit of the seamount (ca. 200m depth) over two and a half years. Twenty‐two of these fish were detected by the receivers but only twelve fish (43%) were detected beyond the two initial days after release. This sub-group of fish was detected at the seamount summit for an average 25% of the days monitored and up to 829days, with a predicted 50% chance of detection at the seamount 278days after release. While at the summit, fish were typically site attached to one side of the seamount summit, particularly at night. Our data indicate that 1) there is high individual variability in the residency at the seamount, ranging from short interspersed visits to year-long residency and 2) the fine-scale movements of blackspot seabream at the Condor seamount could well be characterised by horizontal displacements smaller than previously thought and by frequent diel vertical migrations. This work demonstrates the great potential of acoustic telemetry as a tool to study the habitat use of seamount fishes and to provide information relevant for the spatial management and conservation of these species and habitats. Concurrently, it also highlights the problems and methodological challenges with post-release mortality, particularly in larger individuals, and appropriate receiver coverage, that need to be addressed in future studies.

Fishponds are artificial ecosystems in which biodiversity may be strongly affected by fish farming management. We studied biodiversity variation along a gradient of fish farming intensification within a 180-pond sample of a French region to establish whether biodiversity primarily depended on extensive management with the alternative hypothesis that some habitat characteristics could compensate for the effect of intensification. We compared the relationships of three biodiversity indicators (breeding birds, protected plants, macrophytes) to an index of intensification and to habitat characteristics likely to influence each indicator. In all selected indicators, species richness did not vary according to the composite intensification gradient. Protected plant richness was best explained by periodic drainage, which could thus benefit biodiversity in intensified fishponds provided that shallow littoral areas are still present. Bird richness was linked to macrophyte cover and probably to reed bed areas. Macrophyte richness and coverage were negatively influenced by low water transparency and high fish biomass which seemed likely to affect bird habitat above 350–400 kg/ha. Aquatic vegetation, which may reflect interactive effects of environmental factors and fish farming management, may then contribute to assessment of the ecological status of fishponds under the E.U. Water Framework Directive.

Determining the ecological mechanisms that control population abundances is an important issue for the conservation of endangered and threatened species. We examined whether a threatened bull trout (Salvelinus confluentus) population could coexist at observed levels with the ecologically similar introduced species, lake trout (Salvelinus namaycush), using a pattern-oriented analysis of population dynamics models. We used a large suite of stage- and age-structured models to examine how both competitive and predatory interactions, combined with differing life-history strategies and species vital rates, drove salmonid coexistence patterns. In our models, an ontogenetic shift in juvenile bull trout resource use was the most important factor contributing to the two species coexistence; however, this coexistence occurred with reduced abundances in bull trout that increase the chances of extirpation for the native species. Observed levels of competition were found to have stronger effects than predation on population abundances. We used a pattern-oriented modeling approach to inference; this approach assumes process models that can generate patterns similar to the observed patterns are better supported than those that cannot. This methodology may find wide use on a number of data-limited fishery management and conservation problems.

Greenlandic governance institutions have been criticised for their colonial heritage of centralisation and lack of democratic participation. In the same manner, Greenlandic fisheries management is notorious in the academic literature for its centralised and locally illegitimate character. While recognising the lack of localised co-management fisheries governance institutions in Greenland, we argue that something has yet to be said about power and user participation in the centralised institutions that have developed. From a symbolic interactionist perspective we dissect the centralised institutions in terms of a differentiated cast of actors and their interaction and argue that participation and power come in many institutional guises as the complex cast of actors within the centralised system represent themselves and others. If we are to understand power and participation in Greenlandic fisheries governance, we need to understand the creation of alliances of the subject-positions that seek control of the self-rule fisheries governance decision-making.