Seasonal Fishing Research Articles

Modelling seasonal and geographical n-3 polyunsaturated fatty acid contents in marine fish from the Northeast Atlantic Ocean

Demand for n-3 polyunsaturated fatty acids (n-3 PUFAs) exceeds supply. Large-scale studies on effects of season and geography of n-3 PUFAs in marine fish from the Northeast Atlantic Ocean (NEAO) may be used to optimize utilization and improve nutrition security. Using a sinusoid model, seasonal cycles of n-3 PUFAs were determined and found to be species-specific and clearly pronounced for the pelagic zooplankton feeding species. The Greenland halibut showed very little seasonal variation. The n-3 PUFA content in North Sea autumn-spawning (NSAS) herring peaked in summer, while Norwegian spring-spawning (NSS) herring and mackerel had their peak in autumn. A time shift of peaks in n-3 PUFAs between the two herring stocks was detected, likely due to different spawning strategies in addition to a delay of n-3 PUFAs flux in the northern regions of the NEAO. This study demonstrates that consideration of nutrient contents, such as n-3 PUFAs, when organizing and structuring fishery approaches may improve overall nutritional yield. Based on total annual Norwegian fish landings and seasonal variation in n-3 PUFA contents, n-3 PUFAs yield could theoretically be increased from 13.79 kilo ton per year from the current fishing tactics, to 15.54 if the pelagic species were only caught during the time of their seasonal n-3 PUFA peaks. Pelagic fish is a good source for dietary n-3 PUFAs, but harvest timing will also influence n-3 PUFAs intake by human consumers. One portion of fatty fish harvested during winter/spring may not meet the weekly intake reference nutritional guidelines for n-3 PUFAs. Marine n-3 PUFAs yields also varied geographically and decreased southwards, with the lowest values in Skagerrak. This study can serve as a model to understand patterns of reproductive cycles and geographical distribution of n-3 PUFAs in fatty fish from the NEAO and the novel approach may be useful to support sustainable, seasonal fishing programmes for optimization of n-3 PUFAs yields.

ABUNDANCE AND SPECIES COMPOSITION OF THE FISHES IN BLUE NILE RIVER BELOW THE TISS ISSAT FALL, ETHIOPIA

In the present study we evaluate the relative abundance and species composition of fishes in Blue Nile River below the fall during the wet season (September-October 2010) and dry season (March-April 2011). Fish samples were collected by using monofilaments gillnets (5-55 mm) and multifilament gillnets, having mesh sizes of six, eight, ten, twelve and fourteen centimeter stretched bar mesh, having a length of twenty five meter and depth of one and half meter, on three sampling sites of the Blue Nile River below Tisisat Fall. Eight hundred fifty seven fish specimens that belong to a single class, Actinopeterygii (ray-finned fishes), four orders, and five families and 6 genera were collected. The most dominant species were Labeobarbus intermedius, Labeo forskalii and Mormyrus kannume. The site harbors large flock of L. intermedius population. Sefiana site had the higher diversity (average H'=3.02). Labeobarbus intermedius was the most dominant (39.67% by number) followed by Labeo forskalii (27.77%) and M. kannume (11.67%). The other species, L. nedgia, B. docmak, L. crassibarbis, C. gariepinus and O. niloticus were found in 9.57%, 5.13%, 3.50%, 1.98% and 0.70%, respectively. All fish species except C. gariepinus and O. niloticus were found in all sites. All the fish species except L. crassibarbis, B. docmak and C. gariepinus showed significant differences in abundance between seasons with overall catch composition of 39.67%, 27.77%, 9.57%, and 11.67% for L. intermedius, L .forskalii, L. nedgia and M. kannume, respectively. L. intermedius, L. forskalii, L. nedgia and M. kannume were the most important species in both seasons and in most of the sampling sites. The studied habitats are in danger being eroded and therefore catchment rehabilitation should be considered and the massive seasonal fishing by the local communities should be reduced

Situation des poissons d’eau douce fumés vendus dans les marchés de la ville de Yaoundé (Région du Centre du Cameroun) et évaluation des méthodes de contrôle contre leurs insectes ravageurs au cours du stockage

The smoking, storage and conservation of smoked fish remain the most efficient means of ensuring the almost permanent availability of seasonal fishing products. However, stored smoked fish can be infested by insect pests. The aim of this study was to present the situation of smoked fishes sold in the city of Yaoundé and the methods used by the traders to control insect pests. For this purpose, a study was conducted from October to December 2022 in seven markets in Yaoundé where 65 traders were interviewed mainly on their activities, the origin of smoked fishes and the methods used to control insect pests. The inventory and the quantity of smoked fishes was made in different markets. The storage tools were inspected and the samples of infested smoked fish (commons names) (Catfish, Kanga, Carp, Tilapia, Eel fish, Redtail) and samples of apparently not infested fish (Catfish, Kanga, Carp) were bought from traders according to availability and brought back to laboratory. In the Laboratory, the identification of insect pests was done, the number of insect and the galleries of fish’s collection was counted. It emerges from this study that 80.37% traders are women; according to the age group, 41.44% of traders are between [41-50] years old. 53.67% of traders have a primary education level. Cardboard boxes are the most used tools in fish storage (100%). Six (6) freshwater smoked fish are sold and catfish are the most represented with 2,604 boxes of 50 kg. Dermestes maculatus De Geer 1774 (Coleoptera: Dermestidae) (221 larvae and 54 adults) and Necrobia rufipes De Geer 1775 (Coleoptera: Cleridae) (65 larvae and 37 adults) are the insects pests. Catfish is the smoked fish that revealed the largest number of galleries (86). The chemicals used by traders are Rambo (14.10%) and DD force (24.36%). Mayo-Danay provides 49.86% of smoked fish sold in Yaoundé markets. The ANOVA and Duncan tests have shown that significant differences are observed in the various storage tools and control methods used by traders in the various Yaoundé markets to protect smoked fish from insect pests (p<0.001).

Engineering A Low-Cost Kelp Aquaculture System for Community-Scale Seaweed Farming at Nearshore Exposed Sites via User-Focused Design Process

For over 50 years, government fishery agencies have recognized the need to transition excess fishing capacity in coastal waters to aquaculture. For the most part, investment strategies to move wild capture and harvest efforts into aquaculture have failed since the technology and capital expense for entry, such as large fish pens, was not conducive for acceptance. In contrast, low trophic level aquaculture of shellfish and seaweeds is suitable as an addition to the livelihoods of seasonal fishing communities and to those displaced by fishery closures, especially if vessels and gear can be designed around existing fishing infrastructures, thus allowing fishers to maintain engagement with their primary fishery, while augmenting income via aquaculture. In this study, an inexpensive, lightweight, and highly mobile gear for kelp seaweed farming was developed and tested over a 3-year period in southern Maine, USA. The system was different from existing kelp farming operations used in nearshore waters that use low-scope mooring lines, and heavy, deadweight anchors. Instead, a highly mobile, easy to deploy system using lightweight gear was designed for exposed conditions. The entire system fit into fish tote boxes and was loadable onto a standard pickup truck. The seaweed system had small but efficient horizontal drag embedment anchors connected to a chain catenary and pretensioned with simple subsurface flotation. The system was able to be deployed and removed in less than 4 h by a crew of three using a 10 m vessel and produced a harvest of 12.7 kg/m over an 8-month fall-winter growth period. The target group for this seaweed research and development effort were coastal fishing communities who move seasonally into non-fishing occupations in service industries, such as construction, retail, etc. An economic assessment suggests farmers would realize an 8% return on investment after3 years and $13.50/h greater income as compared to a non-farming off season job at minimum wage. This low-cost seaweed farming system for fall-winter operations fits well into a “livelihood” strategy for fishing families who must work multiple jobs in the offseason when their main fishery is unavailable.

Effect of Fishery Closure on Discard Composition of Rapa Whelk, Rapana venosa (Valenciennes 1846) Beam Trawl Fisheries in Black Sea

Rapa whelk has become significant commercially, as there is a market that makes it export-oriented species. It has also gained special importance because of catching this species in all riparian countries in the Black Sea basin. The various exploitation methods of this species include beam trawl and diving. Here, the experimental beam trawl survey for Rapa whelk fishing was designed monthly in one year. Catch composition was examined spatially and temporally. Differences in estimated biomass of Rapa whelk and abundance of discard species were used to evaluate the effectiveness of seasonal fishing closure. Our results indicated that, discard composition of Rapa whelk fishery strongly reflected seasonal changes. Total estimated abundance and biomass values showed significant regional, seasonal and depth-related differences, also number of species and diversity index changes regionally and seasonally. Discard ratio was found very low in biomass. At the same time, seasonal fishery closure period was benefited for discard species in spring and summer period. The lowest distribution of Rapa whelk and discard species except blood cockle were found in winter season during fishing period. It becomes apparent that seasonal fishery closure is an important management measure both for stock sustainability, species diversity, and ecosystem health. Therefore, all Black Sea countries should consider similar management.

Satellite observation of a newly developed light-fishing “hotspot” in the open South China Sea

Distribution patterns of lit fisheries in the South China Sea (SCS) were investigated using seasonally averaged nighttime light remote sensing data from 2016. Light-fishing activities clearly showed spatial and seasonal patterns and a newly developed “hotspot” with the presence of many intensive lights observed in the open ocean during spring. These satellite observations are consistent with seasonal changes in the fishing grounds of a Chinese large-sized, falling-net fishing fleet based on catch monitoring records for a typical commercial fishing vessel and Vessel Monitoring Systems (VMS) data from this fleet. Catch monitoring records show that this type of vessel operates both on the northern shelf and in the oceanic waters, with apparent seasonal fishing patterns in the SCS. Dominant catches on the shelf include Carangids, Trichiurus japonicus, and Loligo spp., while Sthenoteuthis oualaniensis and Auxis spp. overwhelm catches in the oceanic waters. Furthermore, we compared VMS and Day Night Band (DNB) data to study fishing behaviors of this type of vessel, including match rates between VMS and nightly satellite images and the DNB radiance characteristics of the vessels. This study is valuable for delineating squid fishing grounds in the open SCS and provides an important basis for differentiating light fishing vessels of China from those of other countries, which may be useful for detecting illegal, unreported, and unregulated (IUU) fishing activities. Findings of this study may also shed light on mitigating the emerging threat of light pollution to the local ecosystem of the SCS.

Forecasting community reassembly using climate‐linked spatio‐temporal ecosystem models

Ecosystems are increasingly impacted by human activities, altering linkages among physical and biological components. Spatial community reassembly occurs when these human impacts modify the spatial overlap between system components, and there is need for practical tools to forecast spatial community reassembly at landscape scales using monitoring data. To illustrate a new approach, we extend a generalization of empirical orthogonal function (EOF) analysis, which involves a spatio‐temporal ecosystem model that approximates coupled physical, biological and human dynamics. We then demonstrate its application to five trophic levels for the eastern Bering Sea by fitting to multiple, spatially unbalanced datasets measuring physical characteristics (temperature measurements and climate‐linked forecasts), primary producers (spring and fall size‐fractionated chlorophyll‐a), secondary producers (copepods), juveniles (age‐0 walleye pollock), adult consumers (five commercially important fishes), human activities (seasonal fishing effort) and mobile predators (seabirds). We identify the spatial niche for each ecosystem component, as well as dominant modes of variability that are highly correlated with a known bottom–up driver of dynamics. We then measure spatial overlap between interacting variables (using Schoener's‐D) and identify that age‐0 pollock have decreased spatial overlap with copepods and increased overlap with adult pollock during warm years, and also that adult pollock have increased overlap with arrowtooth flounder and decreased overlap with catcher–processor fishing effort during these warm years. Given the warming conditions that are projected for the coming decade, the model forecasts increased prey and competitor overlap involving adult pollock (between age‐0 pollock, adult pollock and arrowtooth flounder) and decreased overlap with the copepod forage base and with the catcher–processor fishery during future warming. We recommend that joint species distribution models be extended to incorporate ‘ecological teleconnections' (correlations between distant locations arising from known mechanisms) arising from behavioral adaptation by mobile animals as well as passive advection of nutrients and planktonic juvenile stages.

Changing diets and traditional lifestyle of Siberian Arctic Indigenous Peoples and effects on health and well-being.

The diet of Indigenous Peoples of North-Western Siberia is characterized by a significant proportion of traditional foods. Eating local products provides a ready-made set of macro- and microelements necessary for life in the challenging conditions of the Arctic. Currently, high consumption of traditional foods is typical in the season of fishing or reindeer slaughter, while out of season the consumption of easily digestible carbohydrates increases. Due to climate change, seasonal fishing and traditional migration routes are disrupted and, therefore, the consumption of traditional foods is decreasing. During 5 years of expeditions, we performed a cross-sectional screening of 985 Indigenous People from three districts of the Yamal-Nenets Autonomous Okrug. We analyzed the seasonality of acquisition and consumption of local reindeer and fish products and studied the traditional food storage among 90 Indigenous fishermen and hunters, who exploit cryostorage. As diet affects health, we studied the benefits of local food. The duration of the consumption season is decreasing and therefore the amount of consumption of local food is decreasing as well. This has adverse effects on health with increasing hypertension dissemination. The creation of stocks of fish and reindeer meat in villages and their year-round sale to the population is a necessary step for ensuring the food security and health of the inhabitants in the region.

Integrated management of seasonal fishing closures and fisheries stock rebuilding plans for recovering marine stocks in Korea

Integrated management of seasonal fishing closures and fisheries stock rebuilding plans for recovering marine stocks in Korea

Measuring mangrove-fishery benefits in the Peam Krasaop Fishing Community, Cambodia

Whilst previous studies have applied economic value to the ecosystem services mangroves provide to fisheries, most quantitative studies in the peer reviewed literature have limited their measurements to the value provided through a single fishing sector, gear or particular target species group. It can be argued that present research into mangrove-fisheries has not yet represented the full complexity that mangrove-fisheries can encompass in terms of the wide range of people and activities that benefit from the mangrove ecosystem. The reported values of mangroves to fishing livelihoods are therefore likely to fall short of a full valuation. The study provides an all-encompassing value of mangrove benefits to fishing, purposefully investigating the value gained from mangroves through all fishing sectors, fishing activities and target species existing in the Peam Krasaop Fishing Community (PKFC), Koh Kong Province, southwest Cambodia. The ecosystem service value of mangroves for fishing to households in the PKFC was calculated using daily landings volumes collected through semi-structured interviews with fishers, scaled to approximated annual catches. Catch figures were converted to economic value, based on the local market prices given by respondents. Results suggested that the PKFC derives approximately 90% of fishing catch, and 85% of gross income, from mangrove-associated species. Fishing activities are diverse within households; they conduct between 1 and 8 different seasonal fishing activities, spread across mangrove gathering, fishing by boat and mariculture. This study provides a higher estimated proportion of mangrove-associated catches than many studies of fishing communities elsewhere. It may be the case that the PKFC does not have higher levels of mangrove dependency than other mangrove-fisheries. Rather, this study may provide a better quantification of mangrove value than has previously been achieved. Further studies along the same lines, taking a similarly holistic approach to mangrove-fishery valuation, are necessary to test this proposition.

Characterizing seasonal fishing patterns and growth dynamics during the Middle and Late Holocene in the Strait of Magellan (Chilean Patagonia): Sclerochronological analysis of tadpole codling (Salilota australis) vertebrae

We describe sclerochronological analyses of tadpole codling (Salilota australis) vertebrae as a proxy for the seasonal timing of fishing activities at one Middle Holocene (6500 BP) and three Late–Middle Holocene (3500–2500 years BP) archaeological sites located in Seno Otway and in the central zone of the Strait of Magellan, Chile. These data provide an approximation of the population characteristics of the species in the past by estimating the relationship between size and age of the archaeological fish and comparing their growth rate to those of modern specimens captured monthly over one year. The results showed that the size at age was significantly larger in archaeological samples than in the modern reference collection. Our results indicate that fishing activities took place throughout the year at the Late Holocene sites, with a special emphasis on the cold season, while the Middle Holocene site showed a tendency to catch tadpole codling during the warm season.

Fishers' solutions for hammerhead shark conservation in Peru

Filling ecological and social data gaps for small-scale fisheries is crucial for global conservation of shark species. In 2016, international protection of vulnerable smooth hammerhead sharks (Sphyrna zygaena) resulted in a seasonal fishing ban to protect juvenile sharks in Peru's small-scale fisheries. Richer data on the fisheries' social-ecological dynamics are necessary to understand fishery impacts and the ban's efficacy. Semi-structured interviews with 88 Peruvian gillnetters revealed that fishers are cognizant of their impacts on the hammerhead population and further, that historical fishery impacts on the species are more severe than reflected in official records. On balance, respondents welcome conservation measures: 76% of respondents were in favor of the ban. However, most respondents also voiced objections to the ban, with unfairness emerging as a central theme including with regards to impracticality, economic severity, ecological necessity, and the burden of compliance. These objections may directly and indirectly stem from a lack of transparency and fisher participation in the ban development-and-implementation process. Fishers suggested alternative or additional options for hammerhead management, such as minimum sizes or dynamic “move-on” spatial closures. These results point to the benefits of a participatory process that engages fishers in practical and more equitable conservation solutions.

Good news from the Cayman Islands

Conservation Groupers are large tropical marine fish that show remarkable mass-spawning behaviors. Predictably, regular aggregations of large fish make easy targets for exploitation by fishermen. As a result, an important food species, the Nassau grouper ( Epinephelus striatus ), has become critically endangered throughout the Caribbean. Waterhouse et al. show how coordinated management action over 15 years among government personnel, academics, and nonprofit organizations has been effective in replenishing the species on Little Cayman in the Cayman Islands. Spatial and seasonal fishing closures were implemented, supported by a stock monitoring program. A combination of modeling and diver-based census shows that the population of this species has tripled locally. Similar programs could be adopted elsewhere in tropical fisheries where mass-spawning species are vulnerable to overexploitation. Proc. Natl. Acad. Sci. U.S.A. 10.1073/pnas.1917132117 (2020).

“In search of a good life”: Perspectives on village out-migration in a Tanzanian marine park

Abstract This paper draws from ethnographic fieldwork conducted between August–October 2014 and July–August 2015 in a rural village located inside of a Tanzanian marine park. Through narrative responses elicited during interviews with village residents, coupled with ethnographic vignettes from a key interlocutor in the village, the paper reveals people's diverse perspectives on village out-migration. In doing so, it interrogates the claim that the marine park has forced people to out-migrate. Some respondents explained that men generally engage in circular forms of labour-related mobility in the context of seasonal fishing activities and short-term business ventures. Others said that people choose to out-migrate due to everyday hardships, leaving “in search of a good life.” These narrative responses are at once commentaries on the macro-level political and economic drivers of rural out-migration, and on respondent's micro-level aspirations for future socioeconomic autonomy. Thus, they are both expressions of structural constraint and individual agency. While very few interviewees believed that people were forced to migrate because of the marine park, most respondents contended that it had deepened pre-existing experiences of a “hard life,” and exacerbated lived experiences of vulnerability. However, migration has historically been woven into the sociocultural fabric of the community, and there are broader trends of rural population mobility in Tanzania, and fisher mobility in coastal areas, which long pre-date the establishment of the park. Furthermore, some respondents offered alternative narratives, noting that villagers may choose not to out-migrate, and that village in-migration may be increasing due to various pull factors. As such, the paper complicates the scholarly discourse on the relationship between marine protected areas and displacement of local communities.

The key role of the Northern Mozambique Channel for Indian Ocean tropical tuna fisheries

The Northern Mozambique Channel (NMC) is a tropical area of ~ 1 million km2 where pelagic fisheries supply proteins to more than 9 million people living in Comoros, Mayotte, and along the coasts of Mozambique, Tanzania and Madagascar. Although uncertain, statistics suggest that about 20,000 mt of tropical tuna and other pelagic fish are annually caught by artisanal fisheries in the area. The NMC is also a major seasonal fishing ground for high-seas fleets that export an annual average catch of more than 20,000 mt to tuna can and sashimi markets of high-income countries for a value estimated to be more than 100 million USD. The fisheries productivity of the NMC appears to be highly variable in relation to strong annual and seasonal variability in oceanographic conditions. Our review shows that the NMC is a key feeding area for tropical tunas and a major spawning area for skipjack tuna thanks to warm waters and strong mesoscale activity that results in the enrichment of surface waters and efficient energy transfers enabled by short food chains. Projections of climate models under future warming scenarios predict some strong changes in the oceanographic conditions of the NMC which has already experienced substantial warming over the last decades. Changes in the pelagic ecosystem of the NMC could have dramatic consequences on the coastal populations that are expected to increase towards 100 million people by 2100. Improving monitoring systems and collecting information on the socio-economics of coastal fisheries is crucial to assess the dependence of NMC populations on tuna resources and empower the countries to more involvement in the management of tuna stocks.

MODIS Derived Sea Surface Salinity, Temperature, and Chlorophyll-a Data for Potential Fish Zone Mapping: West Red Sea Coastal Areas, Saudi Arabia.

In this study, a multi-linear regression model for potential fishing zone (PFZ) mapping along the Saudi Arabian Red Sea coasts of Yanbu’ al Bahr and Jeddah was developed, using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data derived parameters, such as sea surface salinity (SSS), sea surface temperature (SST), and chlorophyll-a (Chl-a). MODIS data was also used to validate the model. The model expanded on previous models by taking seasonal variances in PFZs into account, examining the impact of the summer, winter, monsoon, and inter-monsoon season on the selected oceanographic parameters in order to gain a deeper understanding of fish aggregation patterns. MODIS images were used to effectively extract SSS, SST, and Chl-a data for PFZ mapping. MODIS data were then used to perform multiple linear regression analysis in order to generate SSS, SST, and Chl-a estimates, with the estimates validated against in-situ data obtained from field visits completed at the time of the satellite passes. The proposed model demonstrates high potential for use in the Red Sea region, with a high level of congruence found between mapped PFZ areas and fish catch data (R2 = 0.91). Based on the results of this research, it is suggested that the proposed PFZ model is used to support fisheries in determining high potential fishing zones, allowing large areas of the Red Sea to be utilized over a short period. The proposed PFZ model can contribute significantly to the understanding of seasonal fishing activity and support the efficient, effective, and responsible use of resources within the fishing industry.

Seasonal trend of Anisakidae infestation in South Mediterranean bluefish

A total of 1104 fish samples from markets of Sicily were analysed for the detection and species identification of Anisakidae nematodes. The preliminary analysis of the fish samples showed the presence of 2459 larvae. All the fish species revealed different prevalence of infestation, with a maximum of 100% for Lepidopus caudatus and a minimum of 4.5% in Sardina pilchardus. The 80% of the larvae examined by PCR-RFLP analysis belonged to Anisakis pegreffii species. The seasonal infestation trend of Anisakis was evaluated in all the fish sample examined. The results of the seasonal infestation trend showed a marked connection with the ecological aspects of the fish species examined. As far as we know, this work report for the first time important ecological aspects of Lepidopus caudatus specimens of South Mediterranean. This work could be useful to plan a seasonal fishing strategy aimed at reducing the health risks related to Anisakis.

Fishing Season of Large Tuna from Purse Seine Fishery in Tumumpa, Manado, North Sulawesi

Knowledge on seasonal fishing pattern is essential in fisheries research in order to increase the effectiveness of fishing and at the same time protecting the fishing ground from excessive fishing practices. Determining the seasonal fishing pattern of large pelagic fishes, namely large tuna (yellowfin and bigeye), small tuna (mackerel) and skipjack tuna were the objective of this study. Data from the 2013-2015 fishing operation time series were used to analyze the fishing season using the percentage average per unit effort (CPUE) method. The main focus of this study was purse seine fishery. The research showed that high fishing season of large pelagic fishes allegedly occurred during May to July, which reached its peak on May. On the other hand, low fishing season occurred during January to April, with the lowest on March. There were similarities between large tuna, small tuna and skipjack in term of their seasonal fishing pattern, although they did not show any good correlation (r<0.5). This might due to fact that even tough large tuna, small tuna and skipjack tuna shared the same ecological niche but apparently, they did not show any interaction (symbiosis) but competition.

Modeling temporal closures in a multispecies recreational fishery reveals tradeoffs associated with species seasonality and angler effort dynamics

Seasonal closures are commonly used to reduce fishing mortality in recreational and commercial fisheries, but they may be less effective when effort is merely displaced to the open season or in multispecies fisheries that allow for discarding to continue while other species are targeted. The latter is especially true for the valuable multispecies recreational reef fish fishery in the Gulf of Mexico, where discard mortality is high and it can be difficult to avoid catching one species while fishing for others. We evaluated the utility of complete bottom fishing closures (in addition to already mandated harvest closures) that would temporarily prohibit recreational reef fishing as a means to control effort, reduce the amount of dead discards, and improve stock status of multiple species. In this study we developed age-structured population models for six Gulf of Mexico reef fish species that dominate the recreational catch, with each model linked to a monthly effort dynamic model for the recreational fishery. The effect of closing any given month(s) varied across species and resulted in tradeoffs, such that some closures may result in positive effects on biomass of one species and negative effects on others. For example, a spring closure was predicted to have positive effects on Red Snapper Lutjanus campechanus spawning stock biomass but negative effects on Gag grouper Mycteroperca microlepis due to the contrasting patterns in harvest rates during those months. These tradeoffs were associated with seasonal availability patterns and the degree to which anglers might shift effort to the open season. The closure scenarios that were most likely to reduce dead discards without negatively impacting harvest, spawning biomass, or total effort occurred in late winter and early spring (March & April). In evaluating seasonal fishing closures, the gains in biomass and reductions in dead discards must be weighed against the socio-economic tradeoffs, in terms of lost effort-generated revenue at various spatial and temporal scales and angler dissatisfaction.

Flood risk‐benefit assessment to support management of flood‐prone lands

Flood risk assessments often overlook benefits of floodplain use and the influence of coping capacity. Herein we present a classic flood risk analysis, but simultaneously evaluate benefits of flood‐prone land use in Candaba, Philippines. By combining simulated flood probabilities with both damage and benefit functions, we estimate agricultural damages and livelihood benefits over flood hazards of varying frequency. We find that concurrent evaluation of both damages and benefits provides more complete information on which flood risk reduction decisions may be based. In Candaba, although “risky” uses of flood‐prone land are associated with rice‐crop damages, livelihood benefits exceed risks by a large margin (US $58 million) across the range of investigated flood hazards. Even considering risk, net benefits of direct human floodplain use far exceed benefits provided when direct “risky” human uses are excluded (difference of $85–87 million). We also find that individual coping strategies (adapting crop cycles to the flood pulse or shifting from farming to seasonal fishing) may minimise flood losses while supporting livelihood benefits (net benefit of $125 million). Risk‐benefit analysis can support floodplain management by elucidating practices that yield maximum socio‐ecological benefits for the minimum flood risk.