scholarly journals Unravelling the macro-evolutionary ecology of fish–jellyfish associations: life in the ‘gingerbread house’

2019 ◽  
Vol 286 (1899) ◽  
pp. 20182325 ◽  
Author(s):  
Donal C. Griffin ◽  
Chris Harrod ◽  
Jonathan D. R. Houghton ◽  
Isabella Capellini
Keyword(s):  
Evolutionary Dynamics ◽  
Evolutionary Ecology ◽  
Juvenile Fish ◽  
Fish Mortality ◽  
Fish Stock ◽  
Fish Stocks ◽  
Evolutionary Consequence ◽  
Marine Habitats ◽  
Complex Process ◽  
Wide Scale

Fish–jellyfish interactions are important factors contributing to fish stock success. Jellyfish can compete with fish for food resources, or feed on fish eggs and larvae, which works to reduce survivorship and recruitment of fish species. However, jellyfish also provide habitat and space for developing larval and juvenile fish which use their hosts as means of protection from predators and feeding opportunities, helping to reduce fish mortality and increase recruitment. Yet, relatively little is known about the evolutionary dynamics and drivers of such associations which would allow for their more effective incorporation into ecosystem models. Here, we found that jellyfish association is a probable adaptive anti-predator strategy for juvenile fish, more likely to evolve in benthic (fish living on the sea floor), benthopelagic (fish living just above the bottom of the seafloor), and reef-associating species than those adapted to other marine habitats. We also found that jellyfish association likely preceded the evolution of a benthic, benthopelagic, and reef-associating lifestyle rather than its evolutionary consequence, as we originally hypothesized. Considering over two-thirds of the associating fish identified here are of economic importance, and the wide-scale occurrence and diversity of species involved, it is clear the formation of fish–jellyfish associations is an important but complex process in relation to the success of fish stocks globally.

scholarly journals Indicators of AEI Applied to the Delaware Estuary

2002 ◽  
Vol 2 ◽  
pp. 169-189 ◽  
Author(s):  
Lawrence W. Barnthouse ◽  
Douglas G. Heimbuch ◽  
Vaughn C. Anthony ◽  
Ray W. Hilborn ◽  
Ransom A. Myers
Keyword(s):  
Meta Analysis ◽  
Juvenile Fish ◽  
Fish Populations ◽  
Weight Of Evidence ◽  
Data Sets ◽  
Delaware Estuary ◽  
Fish Stocks ◽  
Trends Analysis ◽  
Definition Of

We evaluated the impacts of entrainment and impingement at the Salem Generating Station on fish populations and communities in the Delaware Estuary. In the absence of an agreed-upon regulatory definition of “adverse environmental impact” (AEI), we developed three independent benchmarks of AEI based on observed or predicted changes that could threaten the sustainability of a population or the integrity of a community.Our benchmarks of AEI included: (1) disruption of the balanced indigenous community of fish in the vicinity of Salem (the “BIC” analysis); (2) a continued downward trend in the abundance of one or more susceptible fish species (the “Trends” analysis); and (3) occurrence of entrainment/impingement mortality sufficient, in combination with fishing mortality, to jeopardize the future sustainability of one or more populations (the “Stock Jeopardy” analysis).The BIC analysis utilized nearly 30 years of species presence/absence data collected in the immediate vicinity of Salem. The Trends analysis examined three independent data sets that document trends in the abundance of juvenile fish throughout the estuary over the past 20 years. The Stock Jeopardy analysis used two different assessment models to quantify potential long-term impacts of entrainment and impingement on susceptible fish populations. For one of these models, the compensatory capacities of the modeled species were quantified through meta-analysis of spawner-recruit data available for several hundred fish stocks.All three analyses indicated that the fish populations and communities of the Delaware Estuary are healthy and show no evidence of an adverse impact due to Salem. Although the specific models and analyses used at Salem are not applicable to every facility, we believe that a weight of evidence approach that evaluates multiple benchmarks of AEI using both retrospective and predictive methods is the best approach for assessing entrainment and impingement impacts at existing facilities.

scholarly journals Dictionary-Based Method for Fishing Gear Pattern Detection

10.29007/npz9 ◽  
2019 ◽  
Author(s):  
Ramón Aranda ◽  
Hugo Carlos
Keyword(s):  
Coastal Communities ◽  
Pattern Detection ◽  
Upper Paleolithic ◽  
Fishing Gear ◽  
Fish Stocks ◽  
Iuu Fishing ◽  
Marine Habitats ◽  
Automatic Information ◽  
Fishing Fleets ◽  
Unregulated Fishing

Fishing is an ancient practice that dates back to at least the beginning of the Upper Paleolithic period about 40,000 years ago. Nowadays, Fishing is one of the most important activities, as it provides a source of food and economic income worldwide. A key challenge in ecology and conservation is to decrease the Illegal, Unreported and Unregulated fishing (IUU). IUU fishing depletes fish stocks, destroys marine habitats, distorts competition, puts honest fishers at an unfair disadvantage, and weakens coastal communities, particularly in developing countries. One strategy to decrease the IUU fishing is monitoring and detecting the fishing vessel behaviors. Satellite–based Automatic Information Systems (S– AIS) are now commonly installed on most ocean–going vessels and have been proposed as a novel tool to explore the movements of fishing fleets in near real time. In this article, we present a dictionary–based method to classify, by using AIS data, between two fishing gear types: trawl and purse seine. The data was obtained from Global Fishing Watch. Our experiments show that our proposal has a good performance in classifying fishing behaviors, which could help to prevent overexploit and improve the strategies of the fisheries management.

scholarly journals Economic effort management in multispecies fisheries: the FcubEcon model

2010 ◽  
Vol 67 (8) ◽  
pp. 1802-1810 ◽  
Author(s):  
Ayoe Hoff ◽  
Hans Frost ◽  
Clara Ulrich ◽  
Dimitrios Damalas ◽  
Christos D. Maravelias ◽  
...  
Keyword(s):  
Single Species ◽  
Fish Stock ◽  
Economic Optimization ◽  
Management Tools ◽  
Management Framework ◽  
Fish Stocks ◽  
Effort Allocation ◽  
Multispecies Fisheries ◽  
The Past ◽  
Quota Management

Abstract Hoff, A., Frost, H., Ulrich, C., Damalas, D., Maravelias, C. D., Goti, L., and Santurtún, M. 2010. Economic effort management in multispecies fisheries: the FcubEcon model. – ICES Journal of Marine Science, 67: 1802–1810. Applying single-species assessment and quotas in multispecies fisheries can lead to overfishing or quota underutilization, because advice can be conflicting when different stocks are caught within the same fishery. During the past decade, increased focus on this issue has resulted in the development of management tools based on fleets, fisheries, and areas, rather than on unit fish stocks. A natural consequence of this has been to consider effort rather than quota management, a final effort decision being based on fleet-harvest potential and fish-stock-preservation considerations. Effort allocation between fleets should not be based on biological considerations alone, but also on the economic behaviour of fishers, because fisheries management has a significant impact on human behaviour as well as on ecosystem development. The FcubEcon management framework for effort allocation between fleets and fisheries is presented, based on the economic optimization of a fishery's earnings while complying with stock-preservation criteria. Through case studies of two European fisheries, it is shown how fishery earnings can be increased significantly by reallocating effort between fisheries in an economically optimal manner, in both effort-management and single-quota management settings.

Management of evolving fish stocks

1998 ◽  
Vol 55 (8) ◽  
pp. 1971-1982 ◽  
Author(s):  
Mikko Heino
Keyword(s):  
Maximum Sustainable Yield ◽  
Evolutionary Change ◽  
Fish Stock ◽  
Sustainable Yield ◽  
Harvest Rate ◽  
Fish Stocks ◽  
Population Dynamics Model ◽  
Before And After ◽  
Age Structured ◽  
Delayed Maturation

Mortality caused by harvesting can select for life history changes in the harvested stock. Should this possibility be taken into account in the management of renewable resources? I compare the performance of different harvest strategies when evolutionary change is accounted for with the help of an age-structured population dynamics model. Assuming that age of first reproduction is the only evolving trait, harvesting of only mature individuals selects for delayed maturation and results in increased sustainable yields. Unselective harvesting of both mature and immature fish selects for earlier maturation which causes the sustainable yield to decrease. Constant stock size and constant harvest rate strategies perform equally well in terms of maximum sustainable yield, both before and after evolutionary change. The maximum sustainable yield for fixed-quota strategies is lower. All those strategies have similar evolutionary consequences given a similar average harvest rate. Coevolutionary dynamics between fish stock and the stock manager indicate that the evolutionary benefits of selective harvesting are attainable without incurring yield losses in the near future.

scholarly journals Population variability under stressors is dependent on body mass growth and asymptotic body size

2020 ◽  
Vol 7 (2) ◽  
pp. 192011
Author(s):  
Leonie Färber ◽  
Rob van Gemert ◽  
Øystein Langangen ◽  
Joël M. Durant ◽  
Ken H. Andersen
Keyword(s):  
Body Mass ◽  
Life Histories ◽  
Random Noise ◽  
Fish Stock ◽  
Vital Rates ◽  
Anthropogenic Pressures ◽  
Fish Stocks ◽  
Asymptotic Size ◽  
Wide Range ◽  
Stock Recruitment

The recruitment and biomass of a fish stock are influenced by their environmental conditions and anthropogenic pressures such as fishing. The variability in the environment often translates into fluctuations in recruitment, which then propagate throughout the stock biomass. In order to manage fish stocks sustainably, it is necessary to understand their dynamics. Here, we systematically explore the dynamics and sensitivity of fish stock recruitment and biomass to environmental noise. Using an age-structured and trait-based model, we explore random noise (white noise) and autocorrelated noise (red noise) in combination with low to high levels of harvesting. We determine the vital rates of stocks covering a wide range of possible body mass (size) growth rates and asymptotic size parameter combinations. Our study indicates that the variability of stock recruitment and biomass are probably correlated with the stock's asymptotic size and growth rate. We find that fast-growing and large-sized fish stocks are likely to be less vulnerable to disturbances than slow-growing and small-sized fish stocks. We show how the natural variability in fish stocks is amplified by fishing, not just for one stock but for a broad range of fish life histories.

scholarly journals Effective fisheries management instrumental in improving fish stock status

2020 ◽  
Vol 117 (4) ◽  
pp. 2218-2224 ◽  
Author(s):  
Ray Hilborn ◽  
Ricardo Oscar Amoroso ◽  
Christopher M. Anderson ◽  
Julia K. Baum ◽  
Trevor A. Branch ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Food System ◽  
Fish Stock ◽  
Management Tools ◽  
Fish Stocks ◽  
Fisheries Science ◽  
The World ◽  
Fish Catch ◽  
Intensively Managed

Marine fish stocks are an important part of the world food system and are particularly important for many of the poorest people of the world. Most existing analyses suggest overfishing is increasing, and there is widespread concern that fish stocks are decreasing throughout most of the world. We assembled trends in abundance and harvest rate of stocks that are scientifically assessed, constituting half of the reported global marine fish catch. For these stocks, on average, abundance is increasing and is at proposed target levels. Compared with regions that are intensively managed, regions with less-developed fisheries management have, on average, 3-fold greater harvest rates and half the abundance as assessed stocks. Available evidence suggests that the regions without assessments of abundance have little fisheries management, and stocks are in poor shape. Increased application of area-appropriate fisheries science recommendations and management tools are still needed for sustaining fisheries in places where they are lacking.

scholarly journals Flawed evidence supporting the Metabolic Theory of Ecology may undermine goals of ecosystem-based fishery management: the case of invasive Indo-Pacific lionfish in the western Atlantic

2016 ◽  
Vol 74 (5) ◽  
pp. 1256-1267
Author(s):  
Diego Valderrama ◽  
KathrynAnn H. Fields
Keyword(s):  
Fishery Management ◽  
Environmental Temperature ◽  
Growth Parameters ◽  
Fish Mortality ◽  
Natural Mortality ◽  
Metabolic Theory ◽  
Prey Fish ◽  
Western Atlantic ◽  
Fish Stocks ◽  
Metabolic Theory Of Ecology

Given its ability to yield predictions for very diverse phenomena based only on two parameters—body size and temperature—the Metabolic Theory of Ecology (MTE) has earned a prominent place among ecology’s efficient theories. In a seminal article, the leading proponents of the MTE claimed that the theory was supported by evidence from Pauly’s (On the interrelationships between natural mortality, growth parameters, and mean environmental temperature in 175 fish stocks. Journal Du Conseil International Pour L’Exploration de la mer 39:175–192) dataset on natural mortality, biomass, and environmental temperature for 175 fish stocks spanning tropical, temperate, and polar locations. We demonstrate that the evidence presented by the proponents of the MTE is flawed because it fails to account for the fact that Pauly re-estimated environmental temperatures for polar fish as ‘physiologically effective temperatures’ to correct for their ‘abnormally’ high natural (mass-corrected) mortalities, which on average turned out to be similar to (rather than lower than) the mortalities recorded for temperate fish. Failing to account for these modifications skews the coefficients from MTE regression models and wrongly validates predictions from the theory. It is important to point out these deficiencies given the broad appeal of the MTE as a theoretical framework for applied ecological research. In a recent application, the MTE was used to estimate biomass production rates of prey fish in a model of invasive Indo-Pacific lionfish (Pterois volitans and P. miles) predation in Bahamian reefs. We show that the MTE coefficients may lead to a drastic overestimation of prey fish mortality and productivity rates, leading to erroneous estimations of target densities for ecological control of lionfish stocks. A set of robust mortality-weight coefficients is proposed as an alternative to the MTE.

scholarly journals Estimating the mortality caused by great cormorant predation on fish stocks: pikeperch in the Archipelago Sea, northern Baltic Sea, as an example

2016 ◽  
Vol 73 (1) ◽  
pp. 84-93 ◽  
Author(s):  
Outi Heikinheimo ◽  
Pekka Rusanen ◽  
Katja Korhonen
Keyword(s):  
Age Groups ◽  
Total Mortality ◽  
Sensitivity Analyses ◽  
Fish Stock ◽  
Great Cormorant ◽  
Phalacrocorax Carbo ◽  
Fish Stocks ◽  
Archipelago Sea ◽  
Phalacrocorax Carbo Sinensis ◽  
The Impact

Estimates of the mortality rates caused by cormorants are needed to assess the impact on fish stock dynamics and fisheries. In this study, we calculated the annual instantaneous mortality caused by great cormorants (Phalacrocorax carbo sinensis) on young pikeperch (Sander lucioperca), using data from Archipelago Sea, southwestern coast of Finland. The pikeperch are vulnerable to cormorant predation mainly at the ages 2–4. The annual instantaneous mortality caused by cormorants was between 0.04 and 0.13, and the estimated effect on the pikeperch stock size at recruitment to the fishery ranged from 4% to 23%, respectively. The average annual cormorant-induced mortality accounted for 5%–34% of the total mortality in these age groups. The sensitivity analyses proved that the rates of mortality from other sources largely affect the estimated mortality from cormorant predation. In cases with strong fluctuations in the abundance of the prey fish stocks, ignoring the size and density dependence of the natural mortality may lead to overestimation of the importance of cormorants as competitors of fisheries.

scholarly journals Detecting regime shifts in fish stock dynamics

2015 ◽  
Vol 72 (11) ◽  
pp. 1619-1628 ◽  
Author(s):  
Tommi Perälä ◽  
Anna Kuparinen
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Stock Assessment ◽  
Detection Algorithm ◽  
Regime Shifts ◽  
Change Point Detection ◽  
Fish Stock ◽  
Fish Stocks ◽  
Data Generating Process ◽  
Change In Mean

Environmental factors such as water temperature, salinity, and the abundance of zooplankton can have major effects on certain fish stocks’ ability to produce juveniles and, thus, stock renewal ability. This variability in stock productivity manifests itself as different productivity regimes. Here, we detect productivity regime shifts by analyzing recruit-per-spawner time series with Bayesian online change point detection algorithm. The algorithm infers the time since the last regime shift (change in mean or variance or both) as well as the parameters of the data-generating process for the current regime sequentially. We demonstrate the algorithm’s performance using simulated recruitment data from an individual-based model and further apply the algorithm to stock assessment estimates for four Atlantic cod (Gadus morhua) stocks obtained from RAM legacy database. Our analysis shows that the algorithm performs well when the variability between the regimes is high enough compared with the variability within the regimes. The algorithm found several productivity regimes for all four cod stocks, and the findings suggest that the stocks are currently in low productivity regimes, which have started during the 1990s and 2000s.

scholarly journals The ambiguous impacts of alternative livelihoods on fisher wellbeing in a closed access fish sanctuary in Port Antonio, Jamaica

2022 ◽  
pp. 263498172110670
Author(s):  
Graham Epstein ◽  
Steven M Alexander ◽  
Melissa Marschke ◽  
Donovan Campbell ◽  
Derek Armitage
Keyword(s):  
Conservation Planning ◽  
Central Feature ◽  
Fish Stocks ◽  
Alternative Livelihoods ◽  
Alternative Livelihood ◽  
Marine Habitats ◽  
Tourism Sector ◽  
Local Stakeholders ◽  
Different Types ◽  
The Relationship

Alternative livelihood programs are a central feature of contemporary conservation planning that aim to aid efforts to reduce pressure on natural resources and avoid, minimize, or mitigate the impacts of conservation on the wellbeing of local stakeholders. Evidence of the effectiveness of these programs is, however, decidedly mixed. This research examines the relationship between livelihoods, conservation, and wellbeing among nearshore fishers in Port Antonio, Jamaica, in the context of a recently established marine no-take area. The East Portland Fish Sanctuary was established in 2016 with the aim of supporting the recovery of depleted nearshore fish stocks, marine habitats, and mitigating impacts on local communities and fishers through a range of activities. Mitigation of impacts included efforts to shift pressure from overexploited nearshore fish stocks to offshore resources and to provide support to fishers for training and opportunities to earn income in the tourism sector. The results suggest that additional sources of income tended to enhance the wellbeing of fishers across several dimensions but that it also contributed to additional pressure on nearshore resources. Furthermore, neither tourism nor offshore fishing appear to be particularly promising in terms of their ability to deliver “win-win” outcomes for conservation and wellbeing. Instead, the results suggest that the impacts of different types of alternative livelihoods on conservation and wellbeing are highly variable and perhaps that efforts should be redirected to supporting efforts to provide suitable and acceptable alternatives to spearfishing which appears to have one of the largest overall impacts on individual harvest rates.

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