Spatial structure of the pink shrimp Penaeus (Farfantepenaeus) notialis (Pérez Farfante, 1967) (Decapoda, Penaeidae) in the Colombian Caribbean: implications for fisheries management

Crustaceana ◽  
2020 ◽  
Vol 93 (9-10) ◽  
pp. 1047-1063
Author(s):  
Argiro Ramírez ◽  
Jorge Paramo ◽  
John Selvaraj

Abstract The objective of this study was to assess the patterns in the spatial distribution, size structure, morphometric relationships, and relationships of biomass and size to sampling depth and distance to the coast of Penaeus notialis in the Colombian Caribbean. The biological data were collected on board a shrimp trawler. The females were larger and heavier than the males, which indicated distinct sexual dimorphism in body size. The cephalothorax length at 50% maturity in females was 26.49 mm, and in males, it was 15.13 mm. Relatively high biomass values were found in the southern zone of the study area at depths between 25.6 and 49.3 m and between 3.94 and 7.80 nmi (= 7.29-14.45 km) from the coast. We found a clear spatial structure of biomass and size in relation to depth, so that the fishing effort can be directed to the locations of the adult population.

<strong><em>Abstract. </em></strong>We review the impacts of towed gears on benthic habitats and communities and predict the consequences of these impacts for ecosystem processes. Our emphasis is on the additive and synergistic large-scale effects of fishing, and we assess how changes in the distribution of fishing activity following management action are likely to affect production, turnover time, and nutrient fluxes in ecosystems. Analyses of the large-scale effects of fishing disturbance show that the initial effects of fishing on a habitat have greater ecosystem consequences than repeated fishing in fished areas. As a result, patchy fishing effort distributions have lower total impacts on the ecosystem than random or uniform effort distributions. In most fisheries, the distribution of annual fishing effort within habitats is more patchy than random, and patterns of effort are maintained from year to year. Our analyses suggest that many vulnerable species and habitats have only persisted in heavily fished ecosystems because effort is patchy. Ecosystem-based fisheries management involves taking account of the ecosystem effects of fishing when setting management objectives. One step that can be taken toward ecosystem-based fisheries management is to make an a priori assessment of the ecosystem effects of proposed management actions such as catch controls, effort controls, and technical measures. We suggest a process for predicting the ecosystem consequences of management action. This requires information on habitat distributions, models to predict changes in the spatial distribution of fleets following management action, and models of the impacts of trawling disturbance on ecosystem processes. For each proposed management action, the change in disturbance affecting different habitat types would be predicted and used to forecast the consequences for the ecosystem. These simulations would be used to produce a decision table, quantifying the consequences of alternative management actions. Actions that minimize the ecosystem effects of fishing could then be identified. In data-poor situations, we suggest that management strategies that maintain or maximize the patchiness of effort within habitat types are more consistent with the precautionary approach than those that lead to more uniform fishing effort distributions.


1975 ◽  
Vol 4 (2) ◽  
pp. 195-210 ◽  
Author(s):  
J. M. Gates ◽  
J. M. D'Eugenio

The inshore lobster fishery is one of the more important ones in the Commonwealth of Massachusetts, accounting for approximately 14 percent of the total landed value of all species in Massachusetts in 1971. Until recent years this fishery accounted for virtually all the pot landings in the state. Despite numerous attempts at conservation such as gear regulation, size restrictions, and prohibitions on harvesting egg-bearing females, the fishery has been subject to rapidly increasing effort and virtually constant landings. In the past decade it has become obvious to many fishery biologists and economists that conservation of fish stocks is a necessary but not sufficient criterion for fisheries management. Resource managers have become increasingly aware of the interdependence between economic factors and the intensity, location and composition of fishing effort.


Crustaceana ◽  
2018 ◽  
Vol 91 (2) ◽  
pp. 225-237 ◽  
Author(s):  
César A. Heredia-Delgadillo ◽  
Guillermo Rodríguez-Domínguez ◽  
Raúl Pérez-González ◽  
Nicolás Castañeda-Lomas ◽  
Sergio G. Castillo-Vargasmachuca ◽  
...  

The fishing effort of a Sinaloa crab fishery in the Gulf of California in 2014 was analysed based on fishermen’s interviews, official catches and permits, and information from a sample of fishing logbooks from five fishery cooperatives operating in four coastal lagoons that contained the daily catch from individual fishing trips. Unauthorized gear, a double-ring net (DR), was used most frequently (>70% of the fishers) for crab fishing, although authorized single-ring nets and Chesapeake traps (CT) were also used with low frequency. The estimated fishing effort was 641 boats/day in the four coastal lagoons, which was 34% more than authorized, and 818 boats/day were employed in all of Sinaloa. A total of 57 479 fishing gears were estimated for the study area, which was 49.9% greater than the maximum authorized number, and 80 822 nominal fishing gears were estimated for the entire Sinaloa crab fishery, 14.15% more than the total gear limit (70 800). The size of the mesh used in the gear was smaller than the authorized limit of 76 mm, and >50% of the catches included crabs of unlawful size. It is argued that the effort must be regulated in terms of the number of vessels, per unit time, and not the number of gears. The information from this study demonstrates a failure to monitor compliance with current regulations and thus means that other strategies for the sustainable management of the fishery, such as co-management, should be tested.


1990 ◽  
Vol 47 (6) ◽  
pp. 1194-1205 ◽  
Author(s):  
T. E. Reimchen

In a 112-ha bog lake on the Queen Charlotte Islands, British Columbia, small fish comprised the major element in the diet of cutthroat trout (Oncorhynchus clarki). Despite the presence of juvenile salmon and char in the lake, threespine stickleback (Gasterosteus aculeatus) was the most common fish in the diet (99.5%). Foraging activity appeared to be more frequent in littoral than in limnetic regions. Mark–recapture methods indicate an average population of 220 trout and 75 000 adult stickleback. Trout consumed an estimated 308 770 stickleback yearly (145 kg) of which 65% were taken during summer. Seventy-three percent of all fish consumed were young of the year and 2% were adults, the latter representing 4% of the adult population in the lake. There was a 75% reduction in total mortality between successive year classes of stickleback (0,1,2,3 +). This consumption curve, which resembles a typical survivorship curve of fish, is a function of the size-structure of the populations and includes interactions between size availability of stickleback, prey-size preferences of the trout, and length frequency distributions of trout. Total weight of stickleback consumed by trout comprised about 40% of that previously calculated for 16 species of avian piscivores in the lake.


2001 ◽  
Vol 09 (04) ◽  
pp. 247-254 ◽  
Author(s):  
M. JERRY ◽  
N. RAISSI

This work is composed by two parts: the first part consists of the development and the analysis of a bioeconomical model of fisheries management, where the dynamic is controlled by the variation of the fishing effort; the second part of this work consists of the study of the asymptotical stability of the equilibrium point (stock/fishing effort) of the model; the optimal strategy is described briefly.


2011 ◽  
Vol 68 (4) ◽  
pp. 632-642 ◽  
Author(s):  
Darren M. Parsons ◽  
Mark A. Morrison ◽  
Jeremy R. McKenzie ◽  
Bruce W. Hartill ◽  
Richard Bian ◽  
...  

Intraspecific variation in movement patterns are well established for many species, but poorly appreciated in fisheries management. In this study we dart-tagged snapper ( Pagrus auratus ), an important fishery species, across different areas and habitats in the Hauraki Gulf, New Zealand. Tag returns were used to quantify movement behaviour and extraction rates using a maximum likelihood model that corrected for spatial variability in population size and fishing effort. Residency was high (~90%) in two strata and lower (75%) in the remaining stratum. The stratum with the highest residency also appeared to experience the highest extraction rate (likely due to a lower population size). These results confirm the existence of differences in movement behaviour within the snapper population, suggesting that localized areas may become depleted regardless of the status of the overall stock. This has consequences for the scale of fisheries management and the size of marine reserves implemented in different regions. Understanding why variation in movement behaviour exists (i.e., genetic vs. environmental) is the next step in addressing the influence of animal behaviour on fisheries management.


2013 ◽  
Vol 5 (2) ◽  
pp. 73
Author(s):  
Purwanto Purwanto

<p>Kriteria pengelolaan perikanan dalam kerangka pembangunan nasional, yaitu pro-growth, pro-poor, pro-job dan pro-environment, mengarahkan pengelolaan perikanan udang di Laut Arafura untuk mengoptimumkan produksi lestari dan keuntungan perikanan, serta meningkatkan keuntungan per kapal dan peluang kerja sebagai nelayan. Masing-masing tujuan tersebut perlu ditetapkan angka acuan sasarannya yang diharapkan dicapai dalam pengelolaan perikanan. Mengingat tujuan tersebut saling bertentangan, sehingga tidak dapat dicapai bersamaan, perlu ditentukan tingkat kompromi optimal diantara tujuan tersebut dan angka acuan sasarannya. Tulisan ini menyajikan model pemrograman matematika untuk optimisasi dengan empat tujuan pengelolaan, serta menggunakannya untuk mengestimasi angka acuan sasaran dan jumlah optimal kapal penangkap. Hasil optimisasi dengan pemberian bobot prioritas yang sama terhadap empat tujuan pengelolaan perikanan dalam kerangka pembangunan nasional menunjukkan bahwa angka acuan sasaran pada tingkat kompromi optimal dicapai dengan pengendalian upaya penangkapan pada tingkat yang setara dengan daya tangkap 512 kapal pukat udang 130 GT. Angka acuan sasaran yang sama dihasilkan dari optimisasi dengan pemberian bobot prioritas yang lebih tinggi terhadap dua tujuan pengelolaan perikanan sesuai dengan Pasal 6 Undang Undang Perikanan tahun 2004.</p><p>The criteria of fisheries management undertaken in a framework of national development, particularly pro-growth, pro-poor, pro-job and pro-environment, guide the management of shrimp fishery in the Arafura Sea to optimising shrimp production and fishery profit, and increasing per vessel profit and job opportunity as fishers. As those objectives were conflicting that could not be achieved simultaneously, it is necessary to seek an optimal compromise amongst several conflicting objectives and to estimate their target reference points. This paper presents a mathematical programming model accommodating four objectives of fisheries management, and the utilisation of this for estimating the target reference points and the optimal number of fishing vessels. The result of optimisation shows that target reference points at the optimal compromise levels for the four conflicting objectives, with equal priority, of fisheries management supporting the national development could be achieved by controlling fishing effort at the level equal to fishing power of 512 shrimp trawlers of 130 GT. The same target reference points resulted from the analysis providing higher priority to the objectives of fisheries management stated in Article 6 of Fisheries Act of 2004.</p>


2014 ◽  
Vol 62 (4) ◽  
pp. 1565 ◽  
Author(s):  
Helven Naranjo Madrigal ◽  
Silvia Salas Márquez

Artisanal diving fisheries are a source of income, employment and food security of coastal areas in many countries. Understanding the dynamics of these fisheries, including the spatial and temporal dynamics of fishing effort, gears and species can help to address the challenges involved in fisheries management. We aimed to analyze the differences in fishing strategies undertaken by fishers that use two different diving methods (hookah and free diving), and the conditions and their potential impacts on catches when adjustments to those strategies are applied over time. For this, detailed information of fishing operations from artisanal boats in the North Pacific coast of Costa Rica was analyzed in two fishing seasons (2007-2008 and 2011-2012). Data were collected by onboard observers (fishing site, fishing time, species composition, depth and visibility). Additionally, interviews with divers were applied to obtain information of price per species, species volume and fishing operations. From the total number of trips during both seasons, hookah diving was represented by a sample size of 70.5%, while free diving, with a sample of 69.5%. More than 15 species were identified in each fishing season. Nevertheless, three categories had substantial contributions in both seasons with differences in the proportions for each case: green lobster (<em>Panulirus gracilis</em>), octopus (<em>Octopus</em> sp.) and parrotfish (<em>Scarus perrico</em> and <em>S. ghobban</em>). It is worth noting that an important proportion of catch was retained by fishers for personal consumption purposes, including species of high commercial value. Additional night diving activity, increased the number of dives from one season to another. Besides, cooperation processes in free diving fishing operations, and changes in fishing effort between seasons, defined important changes in fishing strategies. Potential causes of changes in fishing strategies and the implications for management to ensure the sustainability of these fisheries in the long term are discussed.


2013 ◽  
Vol 1 (2) ◽  
pp. 81
Author(s):  
Aldy Adrianus Tatali ◽  
Eddy Mantjoro ◽  
Florence V. Longdong

PERKEMBANGAN EKONOMI SUBSEKTOR PERIKANAN DI KABUPATEN MINAHASA SELATAN PROVINSI SULAWESI UTARA1 Economic Development Fisheries Subsector in the South Minahasa Regency Aldy Adrianus Tatali2, Eddy Mantjoro3, Florence V Longdong3   ABSTRACT The Development of fisheries in North Sulawesi refers to fisheries subsector progress and national marine. Also look at the potential of natural resources, so that fisheries and marine sector to be one of the flagship program of economic development of North Sulawesi. By knowing the great potential of fisheries resources and the development of fishing effort, aquaculture and fisheries management efforts, the government set the fisheries subsector as one driving force of development. Fishermen fishing in coastal South Minahasa regency fishing along the coast and in the Celebes Sea. Most fishermen only catch about 2-3 miles away from the coast. For fishermen purse seine at a distance far enough from the coast 7-12 mill. Mariculture potential to be developed because it is supported by the marine and coastal areas of South Minahasa regency broad and potent. Some commodities, seeded mariculture in South Minahasa Regency is seaweed, grouper, giant travelly (bobara) and sea cucumbers. Production of processed fishery products in South Minahasa Regency is very diverse both in the traditional and modern though. Commodities processed fishery products in the form of wooden fish, salted fish, smoked fish/fufu and bakasang. Keywords : economic, development, fisheries   ABSTRAK Pengembangan usaha perikanan di Sulawesi Utara mengacu pada pembangunan subsektor perikanan dan kelautan nasional. Juga melihat potensi sumberdaya alam, sehingga dari sektor perikanan dan kelautan menjadi salah satu program unggulan pembangunan ekonomi Sulawesi Utara. Dengan mengetahui potensi sumberdaya perikanan yang besar dan perkembangan usaha penangkapan, budidaya dan usaha pengelolaan hasil perikanan maka pemerintah menetapkan subsektor perikanan sebagai salah satu motor penggerak pembangunan. Nelayan perikanan tangkap di pesisir Kabupaten Minahasa Selatan menangkap ikan sepanjang pantai maupun di Laut Sulawesi. Kebanyakan nelayan tradisional hanya menangkap ikan sekitar 2-3 mil jauhnya dari pantai. Bagi nelayan Purse Sein cukup jauh dengan jarak 7-12 mill dari pantai. Budidaya laut sangat potensial untuk dikembangkan karena di dukung oleh wilayah laut dan pesisir Kabupaten Minahasa Selatan yang luas dan potensial. Beberapa komoditi yang menjadi unggulan budidaya laut di Kabupaten Minahasa Selatan adalah rumput laut, ikan kerapu, ikan kuwe (bobara) dan teripang. Produksi olahan hasil perikanan di Kabupaten Minahasa Selatan sangat beragam baik yang di olah secara tradisonal maupun modern. Komoditas olahan hasil perikanan itu berupa ikan kayu, ikan asin, ikan asap/fufu dan bakasang.   Kata kunci : ekonomi, pengembangan, perikanan   1 Bagian dari skripsi 2 Mahasiswa Program Studi Agrobisnis Perikanan FPIK-UNSRAT 3 Staf pengajar Fakultas Perikanan dan Ilmu Kelautan Universitas Sam Ratulangi


Sign in / Sign up

Export Citation Format

Share Document