Measuring the balance between fisheries catch and fish production

2020 ◽  
Vol 643 ◽  
pp. 145-158
Author(s):  
JD Zottoli ◽  
JS Collie ◽  
MJ Fogarty
Keyword(s):  
Fisheries Management ◽  
Gulf Of Maine ◽  
Similarity Index ◽  
Species Level ◽  
Ecosystem Structure ◽  
Fish Production ◽  
Impact Indicator ◽  
Direct Estimate ◽  
Total Fish ◽  
Definition Of

Balanced harvesting has been proposed as a fisheries management strategy to mitigate the impacts of fisheries removal on ecosystem structure. One definition of balanced harvest is that all species should be harvested in proportion to their annual production. However, most marine ecosystems lack comprehensive production estimates necessary to empirically measure the degree of balance. We developed and tested 2 new methods for estimating fish biomass production at the species level with limited data requirements. Application of our techniques to 4 ecological production units in the northwest Atlantic (Mid-Atlantic Bight, Georges Bank, Gulf of Maine, and western Scotian Shelf) from 1991-2013 provided a direct estimate of 1.9 million t yr-1 of total fish production. The degree of balance between catch and production distributions at the species level, assessed using the proportional similarity index, ranged from 0.34 to 0.83 on a scale from near 0 to 1. Increased balance was positively associated with yield in the Gulf of Maine (Spearman’s, p = 0.04). Increased balance was negatively associated with an ecosystem impact indicator in the Gulf of Maine (Spearman’s, p = 0.03) and Mid-Atlantic Bight (Spearman’s, p = 0.02). These case studies provide some evidence of benefit to humans and reduced ecosystem harm from more balanced harvest. More importantly, we provide a unique empirical metric of balanced harvest at the species level, and develop potential indicators and methods for ecosystem-based fisheries management.

Developing a functional definition of small-scale fisheries in support of marine capture fisheries management in Indonesia

Marine Policy ◽  
2019 ◽  
Vol 100 ◽  
pp. 238-248 ◽  
Author(s):  
Abdul Halim ◽  
Budy Wiryawan ◽  
Neil R. Loneragan ◽  
Adrian Hordyk ◽  
M. Fedi A. Sondita ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Small Scale ◽  
Small Scale Fisheries ◽  
Definition Of

An Alternative Perspective on Recruitment Overfishing and Biological Reference Points

1987 ◽  
Vol 44 (4) ◽  
pp. 913-918 ◽  
Author(s):  
M. P. Sissenwine ◽  
J. G. Shepherd
Keyword(s):  
Fisheries Management ◽  
Reference Point ◽  
Reference Points ◽  
Fishing Mortality ◽  
Alternative Perspective ◽  
Conventional Models ◽  
Definition Of ◽  
Yield Per Recruit ◽  
Spawning Biomass

Biological reference points are used to guide fisheries management decisions. The reference points most often used are expressed in terms of fishing mortality rate (F). Fmsy relates to the maximization of sustainable yield. In principle, it is a most useful reference point, but in practice it is difficult to estimate. Fmax and F0.1 relate to certain levels of yield per recruit and are easily estimated, but they ignore conservation of the resource. Recruitment overfishing has usually been understood to occur when a population has been fished down to a point where recruitment is substantially reduced or fails. It has not been used as a basis for a biological reference point because the definition is vague and cannot be readily related to fishing mortality. Levels of spawning biomass below which recruitment seems to be reduced have been used, but their determination from available data is usually difficult and controversial. We propose an alternative definition of recruitment overfishing in terms of the level of fishing pressure that reduces the spawning biomass of a year class over its lifetime below the spawning biomass of its parents on average. Conventional models and types of data can be used to determine this level of F, denoted as Frep, which clearly relates to the replacement of spawning biomass and thus to sustainability of a population and yield in the long term.

scholarly journals Phenology of myxomycetes in Turrialba, Costa Rica

Karstenia ◽  
2021 ◽  
pp. 1-12
Author(s):  
Carlos Rojas ◽  
Pedro A. Rojas ◽  
Steven L. Stephenson
Keyword(s):  
Costa Rica ◽  
Southern Oscillation ◽  
Biological Data ◽  
Species Level ◽  
Ecological Effect ◽  
Sampling Effort ◽  
Ecosystem Structure ◽  
Forest Patch ◽  
Local Climate ◽  
Substrate Quality

Long-term monitoring and phenological patterns of microbial communities are rare in the scientific literature. Myxomycetes have life cycle characteristics that allow both to be documented. The present study summarizes the integrated floristic and bioclimatic components of a 30-month assessment of myxomycete sporocarps in a premontane tropical forest in Turrialba, Costa Rica. Based on monthly visits and a standard sampling effort of 120 minutes per visit, myxomycetes were recorded on leaves, twigs, and logs on the ground by two to three people in 20-minute periods associated with six different collecting sites within a 34-hectare successional forest patch. Biological data were analyzed using three recorded climatic variables obtained <em>in situ</em> during the complete period of study. Also, the Oceanic Niño Index (ONI), provided by NOAA, an estimate of El Niño-Southern Oscillation (ENSO), was evaluated in the analyses. Overall, 54 species and 2245 records of myxomycetes were recorded, with an average of 14.5 species (range between 6-24) and 78.4 records (range between 20-110) detected each month. In general, neither the number of records nor the number of species were associated with individual climate variables, but multiple regression analyses showed that a combination of the accumulated precipitation of the four days before sampling and the average relative humidity can explain most of the fruiting dynamics (R2 = 0.56). When the ONI index was included in the analyses, the explained variability increased (R2 = 0.64), and when a categorization of months based on the same index was used, analyses showed that both the number of records and species evenness were affected by ENSO. At the species level, <em>Hemitrichia calyculata</em> was the only species observed during every month, closely followed by <em>Arcyria cinerea</em>, <em>A. denudata</em>, and <em>Physarum compressum</em>, recorded on most visits. Sporadic fruiting in some species such as <em>Tubifera microsperma</em>, <em>P. tenerum</em>, <em>P. bogoriense</em>, <em>P. melleum</em>, and <em>Metatrichia vesparia</em> could have been associated with local climate oscillations influenced by ENSO patterns. Phenological patterns were observed at the species level, indicating that in the Neotropics, under favorable conditions, myxomycete sporocarps are practically always present, but species assemblages vary temporally. These variations are primarily driven by local climate, but regional climate dynamics also affect fruiting patterns. Presumably, the remaining ecological effect on fruiting patterns in the Neotropics can be attributed to certain finer factors such as ecosystem structure, substrate quality/ availability, and biotic interactions. As such, phenomena such as climate change can have an important effect on the production of sporocarps by tropical myxomycetes, with subsequent effects of their ecological dynamics.

scholarly journals An Estimation of Fish Biomass and Attached Organisms beneath Oyster Rafts in Hiroshima Bay, Japan

2021 ◽  
Vol 324 ◽  
pp. 03013
Author(s):  
Wahyudin Wahyudin ◽  
Tamiji Yamamoto
Keyword(s):  
Large Scale ◽  
Fish Habitat ◽  
Food Chains ◽  
Ecosystem Structure ◽  
Fish Production ◽  
Underwater Video ◽  
Oyster Culture ◽  
Video Cameras ◽  
Black Seabream ◽  
Material Cycles

Hiroshima Bays is top production approximately 60% of oyster production in Japan. For cultivate of oyster, fishermen use hanging rafts. A thousand of raft is hanging during 2-3 years in the bay. Large-scale oyster culture may change the ecosystem structure and material cycles in the bay through the filtration of particulate matter by oysters and other associated animals. This study described the community structure of marine organisme in terms of fishes surrounding and animal attached on oyster rafts. Field observation was carried out from 2016 to 2019 at oyster farming in Hiroshima Bay. Oyster production and provisioning for the fish habitat were also evaluated by placing underwater video cameras beneath oyster culture rafts. The result showed that black seabream was high biomass and oyster it shelf was bigger bioyster for animal attached on oyster raft. The number of individual, mussel is most abundance of animal attach on oyster raft with ratio 9:1 than number of oyster. Maintaining oyster culture is important not only for maintaining oyster production, but also for maintaining fish production by enhancing material cycles through the paths in the food chains of Hiroshima Bay under oligotrophic conditions.

scholarly journals Atlantic puffin diet reflects haddock and redfish abundance in the Gulf of Maine

2020 ◽  
Vol 656 ◽  
pp. 75-87
Author(s):  
KM Depot ◽  
LC Scopel ◽  
SW Kress ◽  
P Shannon ◽  
AW Diamond ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Large Scale ◽  
Gulf Of Maine ◽  
Strong Predictor ◽  
Principal Component ◽  
Melanogrammus Aeglefinus ◽  
Generalist Predator ◽  
Successful Implementation ◽  
Ecosystem Based Fisheries Management ◽  
Atlantic Puffin

Ecosystem-based fisheries management, which considers the interactions between fisheries, target species, and the physical and biological components of ecosystems, is necessary to ensure that directed fisheries avoid adverse impacts to ecosystems over the long term. The successful implementation of ecosystem-based fisheries management requires an understanding of predator-prey relationships and ways to operationalize such relationships to inform fisheries management. Here, we investigated if the diet of a generalist predator, Atlantic puffin Fratercula arctica, can be used as an indicator of the abundance of 2 commercially exploited prey species (haddock Melanogrammus aeglefinus and Acadian redfish Sebastes fasciatus) in the Gulf of Maine. Because haddock and redfish eaten by puffins are juveniles (age 0), there is potential to use their proportions and lengths in puffin diet to better understand the processes influencing haddock and redfish recruitment. By using principal component analysis to develop measures of diet across multiple puffin colonies, we show both spatial variation and large-scale patterns in the proportions and lengths of haddock and redfish in puffin diet. Spawning stock biomass was a strong predictor of haddock proportion in puffin diet and a moderate predictor of redfish proportion; however, proportions in puffin diet did not predict age-1 recruitment, suggesting that variation in recruitment is caused by processes that occur after the puffin breeding season and which affect the survival of older juveniles. Haddock length on one colony was a moderate predictor of age-1 recruitment. We conclude that puffin diet can be used as an indicator of haddock and redfish abundance.

scholarly journals Bridging fisheries management and biodiversity conservation norms: potential and challenges of balancing harvest in ecosystem-based frameworks

2015 ◽  
Vol 73 (6) ◽  
pp. 1659-1667 ◽  
Author(s):  
S. M. Garcia ◽  
J. Rice ◽  
A. Charles
Keyword(s):  
Decision Making ◽  
Fisheries Management ◽  
Biological Diversity ◽  
Population Level ◽  
System Level ◽  
Convention On Biological Diversity ◽  
Management Decision ◽  
Size Spectrum ◽  
Ecosystem Structure ◽  
Management Decision Making

Abstract Balanced harvesting has been proposed as a way for fisheries management to achieve the requirements of both the Law of the Sea Convention (LOSC)—to maintain stocks at the level at which they could produce MSY—and the Convention on Biological Diversity (CBD)—to maintain ecosystem structure and functioning. This paper examines these requirements and briefly presents four system-level relationships (spectra), representing ecosystem structures that might guide management decision-making aiming to meet both requirements. These spectra would fit in the widely accepted frameworks of the Ecosystem Approach enshrined in the CBD and adopted by FAO for Fisheries. A size spectrum, relating biomass to body length, is used as an example to illustrate its potential to support management decision-making—much like present stock-based harvest control rules—in more ecosystem-compliant fishing strategies at a sector or ecosystem level, as a complement to those currently used at a stock/population level.

https://fisheries.org/doi/9781934874301-ch19

2012 ◽  
Keyword(s):  
Ecosystem Services ◽  
High Resolution ◽  
Fisheries Management ◽  
Human Activities ◽  
Gulf Of Maine ◽  
Energy Development ◽  
Benthic Habitat ◽  
Important Species ◽  
Seafloor Mapping ◽  
The U.S

<i>Abstract</i> .—The Gulf of Maine’s seafloor provides a wide array of valuable ecosystem services, including provision of habitat for commercially and ecologically important mammals, seabirds, fish, and invertebrates. Implementing ecosystem-based management will require improved information about the habitats of economically and ecologically important species and the impacts of different human activities, such as fish harvesting, offshore energy development, and shipping, to balance these competing needs. Currently, there is limited high resolution seabed substrate information in the Gulf of Maine, especially in the U.S. portion, because of the high cost of multi-beam echo sounder surveys. Moreover, this lack of coverage limits the ability of managers to use seafloor substrate information in ecosystem management activities, such as fisheries management, that require more holistic coverage of the bioregion. Therefore, the potential need for seafloor mapping in this region is enormous given the value of accurate seafloor information to managers in charge of minimizing impacts to and sustaining the ecosystem services provided by benthic habitat in the Gulf of Maine.

scholarly journals Current status and barriers to fisheries comanagement: Evidences from an Oxbow lake of Bangladesh

2018 ◽  
Vol 46 (2) ◽  
pp. 105-116
Author(s):  
Md Monirul Islam ◽  
Chandan Kar ◽  
Goutam Kumar Kundu ◽  
Gouri Mondal ◽  
Mohammad Shahneawz Khan
Keyword(s):  
Sustainable Management ◽  
Common Property ◽  
Secondary Data ◽  
Oxbow Lake ◽  
Current Status ◽  
Fish Production ◽  
Group Discussions ◽  
Social Barriers ◽  
Institutional Economic ◽  
Total Fish

Co-management of common property aquatic habitats are increasingly implemented with a view to increasing fish production, ensuring fishers’ rights and to conserve biodiversity. This study investigates the current status and identifies barriers to fisheries management in an oxbow lake (baor) at Jessore district, Bangladesh. Using interviews, focus group discussions and secondary data, this study revealed that both capture and culture fisheries are practised at the same time at the same water-body. As the wetland was used solely for capture fisheries before, the introduction of aquaculture practice has increased the total fish production and income for some people. However, it has reduced the access to poor fishers and fish biodiversity. Particularly the biodiversity of Channa sp, Puntius sp, Mastacembelus sp, Mystus sp, and Colisa fasciatus has been reduced. A range of climatic, institutional, economic and social barriers have facilitated the reduced access of poor fishers and biodiversity. To overcome the barriers and ensure sustainable management of the baor this study proposes to implement a fair leasing system, increase financial and human resources together with an ecosystem-based approach to baor management. Bangladesh J. Zool. 46(2): 105-116, 2018

scholarly journals Impact of aqua drugs and chemicals on the recoveries of fish diseases and total fish production in Sherpur region of Bangladesh

2016 ◽  
Vol 1 (3) ◽  
pp. 600-606
Author(s):  
Gias Uddin Ahmed ◽  
Mohammad Nurul Alam ◽  
Md Mamunur Rahman
Keyword(s):  
Potassium Permanganate ◽  
Total Production ◽  
Fish Production ◽  
Average Recovery ◽  
Fish Diseases ◽  
Disease Information ◽  
Different Types ◽  
Liver And Kidney ◽  
Total Fish ◽  
The Impact

The present study was conducted to investigate the impact of aqua-drugs and chemicals on fish health and total fish production in Sherpur region, Bangladesh from July 2014 to June 2015. Forty nine different types of aqua-drugs and chemicals were recorded in the study area; among those sixteen types mainly ADDIC drugs and chemicals were widely used by the farmers for treatment of different fish diseases. It was recorded that GR Plus, Active Blue with Copper sulphate, ID Plus, Aqua c vit and H. vit plus were used for the treatment of EUS in Pangus, Shing and Thai koi which had an average recovery of 80-90%. For the treatment of Edwardsiellosis in Pangus and Thai koi, farmers used GR Plus, ID Plus, OTC power, Aqua c vit, H.vit plus and potassium permanganate which had an average recovery of 75-80%, and for the treatment of dropsy in Thai koi and Shing GR Plus, ID Plus, OTC power, Aqua c vit, H.vit plus and potassium permanganate were used which had an average recovery of 75-85%. Histopathology of liver and kidney of fishes were almost normal in control ponds, whereas, in fish organs from drug treated ponds had pathological changes like necrosis, pyknotic cells, hemorrhage, fat droplet, ilets of langerhens, degeneration of kidney tubules and vacuums. Total production of Thai koi, Shing and Pangus was 10,000 kg/acre, 10,000 kg/acre, and 13,000 kg/acre in drugs treated ponds; whereas, such value was 5,000 kg/acre, 4,500 kg/acre and 6,500 kg/acre in non-treaded ponds, respectively in the study areas. In control ponds, mortality rate was comparatively high and production was also low than drugs treated ponds. End of the experiment, it was observed that efficacy of drugs of Aqua Drug and Disease Information Centre (ADDIC) was excellent.Asian J. Med. Biol. Res. December 2015, 1(3): 600-606

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