Evaluating the influence of predator–prey interactions on stock assessment and management reference points for a large lake ecosystem

2016 ◽  
Vol 73 (9) ◽  
pp. 1372-1388 ◽  
Author(s):  
Hiroyuki Kurota ◽  
Murdoch K. McAllister ◽  
Eric A. Parkinson ◽  
N.T. Johnston
Keyword(s):  
Species Interactions ◽  
Single Species ◽  
Reference Points ◽  
Management Policy ◽  
Management Approach ◽  
Lake Ecosystem ◽  
Large Lake ◽  
Ecosystem Models ◽  
Predator Prey ◽  
Results Management

Ecosystem models are thought to offer advantages over single-species models in terms of management policy analysis. This hypothesis has proven difficult to test because of underlying system complexities, coupled with short time series and minimal contrast in environmental conditions or management policies. This paper presents a Bayesian statistical catch-at-age model to compare ecosystem models and test hypotheses about the management of a recreational fishery based on a predator–prey system using a relatively simple and data-rich ecosystem in a large lake, Kootenay Lake, British Columbia, where kokanee (Oncorhynchus nerka) are the prey and piscivorous rainbow trout (Oncorhynchus mykiss) are the predator. A model that explicitly incorporates the predator–prey interaction explained long-term data of field and fishery surveys much better than single-species models without any interactions. Minimally realistic multispecies models that treated predation identically but differed in their representation of the effects of prey abundance on predator mortality produced quite different results. Management reference points, for example, differed considerably between the models. Our study thus emphasizes that the choice of a management approach for this type of fishery will depend strongly on the model form and should take into consideration results from empirically based models that include species interactions.

Harvesting at the Community Level

2020 ◽  
pp. 205-228
Author(s):  
Michael J. Fogarty ◽  
Jeremy S. Collie
Keyword(s):  
Single Species ◽  
Economic Incentives ◽  
Unintended Consequences ◽  
Community Context ◽  
Reference Points ◽  
Individual Species ◽  
Biological Interactions ◽  
Predator Prey ◽  
The Right ◽  
Technical Solutions

Most fisheries are not directed at individual species alone. Rather, in many instances, species within a community are caught together and are also part of competitive networks and food webs. Species that are caught together are subject to technical interactions. Species that compete or are connected through predator–prey interactions (or other types of interactions) are subject to biological interactions. Ignoring either of these forms of interaction in management can lead to unintended consequences. Technical solutions can help to avoid some species while targeting others, but a comprehensive solution requires creating the right economic incentives and some incidental catch is still inevitable. Accounting for trophic interactions means that biological reference points depend on the abundance of other taxa. Single-species approaches are invalid in a multispecies or community context where biological interactions are important. Technical interactions can make it impossible to achieve target exploitation rates even if biological interactions are relatively unimportant.

Combining stock, multispecies, and ecosystem level fishery objectives within an operational management procedure: simulations to start the conversation

2016 ◽  
Vol 74 (2) ◽  
pp. 552-565 ◽  
Author(s):  
Sarah K. Gaichas ◽  
Michael Fogarty ◽  
Gavin Fay ◽  
Robert Gamble ◽  
Sean Lucey ◽  
...  
Keyword(s):  
Species Interactions ◽  
Life Histories ◽  
Single Species ◽  
Fishing Effort ◽  
Reference Points ◽  
Individual Species ◽  
Management Procedure ◽  
Trade Offs ◽  
Starting Point ◽  
Operational Management

We explored alternative status determination criteria and reference points that could simplify fisheries management using a simulated multispecies/ecosystem-based operational management procedure. There are four components to the procedure: (i) limit total removals from the ecosystem; (ii) allocate the total removals limit among aggregate species groups; (iii) maintain individual species above minimum stock size thresholds; and (iv) optimize the species mix (within aggregates) based on bio-economic portfolio analysis. In this procedure, “overfishing” criteria are applied only to aggregates of species at the ecosystem and group level, but “overfished” criteria apply at the species/stock level. Previous work using multispecies production models identified conditions where conservation and yield objectives could be balanced: aggregations of species with similar life histories, species interactions, and responses to environmental forcing supported the highest yields while minimizing risks that individual stocks dropped below biomass thresholds. Here, we use a more complex length structured multispecies, multifleet simulation model to explore management procedure steps (i)–(iii). Different species aggregation rules were applied (single species, functional groups, and full system), and yield curves were constructed for each aggregation level by sequentially increasing effort in each of the fleets (alone and simultaneously), while recruitment for each species varied stochastically around a function based on spawning stock biomass. The performance of individual species and each aggregate type was then compared with respect to yield, biomass, and economic revenue objectives under changing environmental conditions. Our results evaluate the trade-offs between these objectives for the 10 species in the simulated system. Overall we found that there are aggregate catch limits that can both maximize yield and revenue while conserving biomass. However, community composition and revenue trade-off over a range of fishing effort. We consider this a starting point for further development with scientists, managers, fishermen, and other stakeholders in the region.

scholarly journals Thermal acclimation of interactions: differential responses to temperature change alter predator–prey relationship

2012 ◽  
Vol 279 (1744) ◽  
pp. 4058-4064 ◽  
Author(s):  
Veronica S. Grigaltchik ◽  
Ashley J. W. Ward ◽  
Frank Seebacher
Keyword(s):  
Species Interactions ◽  
Prey Capture ◽  
Thermal Sensitivity ◽  
Single Species ◽  
Thermal Acclimation ◽  
Interspecific Difference ◽  
Ecological Communities ◽  
Predator Prey ◽  
Eastern Mosquitofish ◽  
Species Performance

Different species respond differently to environmental change so that species interactions cannot be predicted from single-species performance curves. We tested the hypothesis that interspecific difference in the capacity for thermal acclimation modulates predator–prey interactions. Acclimation of locomotor performance in a predator (Australian bass, Macquaria novemaculeata ) was qualitatively different to that of its prey (eastern mosquitofish, Gambusia holbrooki ). Warm (25°C) acclimated bass made more attacks than cold (15°C) acclimated fish regardless of acute test temperatures (10–30°C), and greater frequency of attacks was associated with increased prey capture success. However, the number of attacks declined at the highest test temperature (30°C). Interestingly, escape speeds of mosquitofish during predation trials were greater than burst speeds measured in a swimming arena, whereas attack speeds of bass were lower than burst speeds. As a result, escape speeds of mosquitofish were greater at warm temperatures (25°C and 30°C) than attack speeds of bass. The decline in the number of attacks and the increase in escape speed of prey means that predation pressure decreases at high temperatures. We show that differential thermal responses affect species interactions even at temperatures that are within thermal tolerance ranges. This thermal sensitivity of predator–prey interactions can be a mechanism by which global warming affects ecological communities.

scholarly journals The Path to an Ecosystem Approach for Forage Fish Management: A Case Study of Atlantic Menhaden

2021 ◽  
Vol 8 ◽  
Author(s):  
Kristen A. Anstead ◽  
Katie Drew ◽  
David Chagaris ◽  
Amy M. Schueller ◽  
Jason E. McNamee ◽  
...  
Keyword(s):  
United States ◽  
Single Species ◽  
Ecosystem Approach ◽  
The United States ◽  
Reference Points ◽  
Atlantic Menhaden ◽  
Forage Fish ◽  
Ecosystem Models ◽  
Fish Management

Atlantic menhaden (Brevoortia tyrannus) support the largest fishery by volume on the United States East Coast, while also playing an important role as a forage species. Managers’ and stakeholders’ increasing concerns about the impact of Atlantic menhaden harvest on ecosystem processes led to an evolution in the assessment and management of this species from a purely single-species approach to an ecosystem approach. The first coastwide stock assessment of Atlantic menhaden for management used a single-species virtual population analysis (VPA). Subsequent assessments used a forward projecting statistical catch-at-age framework that incorporated estimates of predation mortality from a multispecies VPA while analytical efforts continued toward the development of ecosystem models and explicit ecological reference points (ERPs) for Atlantic menhaden. As an interim step while ecosystem models were being developed, a series of ad hoc measures to preserve Atlantic menhaden biomass for predators were used by managers. In August 2020, the Atlantic States Marine Fisheries Commission formally adopted an ecological modeling framework as a tool to set reference points and harvest limits for the Atlantic menhaden that considers their role as a forage fish. This is the first example of a quantitative ecosystem approach to setting reference points on the United States Atlantic Coast and it represents a significant advance for forage fish management. This case study reviews the history of Atlantic menhaden stock assessments and management, outlines the progress on the current implementation of ERPs for this species, and highlights future research and management needs to improve and expand ecosystem-based fisheries management.

scholarly journals Evaluating Coexistence of Fish Species with Coastal Cutthroat Trout in Low Order Streams of Western Oregon and Washington, USA

Fishes ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Kyle D. Martens ◽  
Jason Dunham
Keyword(s):  
Pacific Northwest ◽  
Species Interactions ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
Single Species ◽  
The Pacific ◽  
Small Streams ◽  
Coastal Cutthroat Trout ◽  
Multiple Species ◽  
Low Order

When multiple species of fish coexist there are a host of potential ways through which they may interact, yet there is often a strong focus on studies of single species without considering these interactions. For example, many studies of forestry–stream interactions in the Pacific Northwest have focused solely on the most prevalent species: Coastal cutthroat trout. To examine the potential for interactions of other fishes with coastal cutthroat trout, we conducted an analysis of 281 sites in low order streams located on Washington’s Olympic Peninsula and along the central Oregon coast. Coastal cutthroat trout and juvenile coho salmon were the most commonly found salmonid species within these streams and exhibited positive associations with each other for both presence and density. Steelhead were negatively associated with the presence of coastal cutthroat trout as well as with coho salmon and sculpins (Cottidae). Coastal cutthroat trout most frequently shared streams with juvenile coho salmon. For densities of these co-occurring species, associations between these two species were relatively weak compared to the strong influences of physical stream conditions (size and gradient), suggesting that physical conditions may have more of an influence on density than species interactions. Collectively, our analysis, along with a review of findings from prior field and laboratory studies, suggests that the net effect of interactions between coastal cutthroat trout and coho salmon do not appear to inhibit their presence or densities in small streams along the Pacific Northwest.

Fishing catch shares in the face of global change: a framework for integrating cumulative impacts and single species management

2010 ◽  
Vol 67 (12) ◽  
pp. 1968-1982 ◽  
Author(s):  
Isaac C. Kaplan ◽  
Phillip S. Levin ◽  
Merrick Burden ◽  
Elizabeth A. Fulton
Keyword(s):  
Global Change ◽  
Ocean Acidification ◽  
Fishery Management ◽  
Single Species ◽  
Ecosystem Model ◽  
Careful Consideration ◽  
Reference Points ◽  
Cumulative Impacts ◽  
English Sole ◽  
Modeling Tools

Any fishery management scheme, such as individual fishing quotas (IFQs) or marine protected areas, should be designed to be robust to potential shifts in the biophysical system. Here we couple possible catch scenarios under an IFQ scheme with ocean acidification impacts on shelled benthos and plankton, using an Atlantis ecosystem model for the US West Coast. IFQ harvest scenarios alone, in most cases, did not have strong impacts on the food web, beyond the direct effects on harvested species. However, when we added the impacts of ocean acidification, the abundance of commercially important groundfish such as English sole ( Pleuronectes vetulus ), arrowtooth flounder ( Atheresthes stomias ), and yellowtail rockfish ( Sebastes flavidus ) declined up to 20%–80%, owing to the loss of shelled prey items from their diet. English sole exhibited a 10-fold decline in potential catch and economic yield when confronted with strong acidification impacts on shelled benthos. Therefore, it seems prudent to complement IFQs with careful consideration of potential global change effects such as acidification. Our analysis provides an example of how new ecosystem modeling tools that evaluate cumulative impacts can be integrated with established management reference points and decision mechanisms.

scholarly journals Sustainable exploitation of temperate fish stocks

2009 ◽  
Vol 6 (1) ◽  
pp. 124-127 ◽  
Author(s):  
Henrik Sparholt ◽  
Robin M. Cook
Keyword(s):  
Species Interactions ◽  
Fishery Management ◽  
Regional Scale ◽  
Single Species ◽  
Fishing Effort ◽  
Theoretical Concept ◽  
Maximum Sustainable Yield ◽  
Production Model ◽  
The Status ◽  
Long Time

The theory of maximum sustainable yield (MSY) underpins many fishery management regimes and is applied principally as a single species concept. Using a simple dynamic biomass production model we show that MSY can be identified from a long time series of multi-stock data at a regional scale in the presence of species interactions and environmental change. It suggests that MSY is robust and calculable in a multispecies environment, offering a realistic reference point for fishery management. Furthermore, the demonstration of the existence of MSY shows that it is more than a purely theoretical concept. There has been an improvement in the status of stocks in the Northeast Atlantic, but our analysis suggests further reductions in fishing effort would improve long-term yields.

Relationships between riverine fish and woody debris: implications for lowland rivers

1999 ◽  
Author(s):  
D. A. Crook ◽  
A. I. Robertson
Keyword(s):  
Woody Debris ◽  
Fish Habitat ◽  
Reference Points ◽  
Positive Development ◽  
Lowland River ◽  
Predator Prey ◽  
Lowland Rivers ◽  
Habitat Features ◽  
Surface Areas ◽  
Riverine Fish

This paper reviews studies of relationships between riverine fish and woody debris at micro- and meso-habitat scales, and discusses the potential functions of instream structure for lowland river fish. Experimental research, mainly in North America, has identified three main functions of woody debris as microhabitat for fish in upland streams: overhead cover that decreases predation risk both vertically and horizontally; horizontal visual isolation that reduces contact between fish; and velocity refuge which minimizes energetic costs. As with habitat features in other aquatic environments, increasing spatial complexity of woody debris may modify predator–prey interactions and provide greater surface areas for the growth of prey items. Woody debris may also provide spatial reference points for riverine fish to assist them in orienting within their surroundings. Lowland rivers differ from upland streams in terms of a number of physical variables, including turbidity, depth and water turbulence. Relationships between fish and woody debris in lowland rivers are likely to rely on mechanisms different to those in upland streams. Recent initiatives involving the reintroduction of woody debris into previously cleared lowland rivers to replace lost fish habitat are a positive development for lowland river restoration. However, if woody debris reintroduction is to maximally benefit lowland river fisheries, there is a requirement for better understanding of the ecological functions of woody debris in lowland rivers.

scholarly journals Impacts of predator-mediated interactions along a climatic gradient on the population dynamics of an alpine bird

2020 ◽  
Author(s):  
Diana E. Bowler ◽  
Mikkel A. J. Kvasnes ◽  
Hans C. Pedersen ◽  
Brett K. Sandercock ◽  
Erlend B. Nilsen
Keyword(s):  
Population Dynamics ◽  
Species Interactions ◽  
Climatic Conditions ◽  
Boreal Ecosystems ◽  
Prey Switching ◽  
Predator Prey ◽  
Classic Theory ◽  
Species Population ◽  
Cyclic Dynamics ◽  
Ground Nesting

AbstractAccording to classic theory, species’ population dynamics and distributions are less influenced by species interactions under harsh climatic conditions compared to under more benign climatic conditions. In alpine and boreal ecosystems in Fennoscandia, the cyclic dynamics of rodents strongly affect many other species, including ground-nesting birds such as ptarmigan. According to the ‘alternative prey hypothesis’ (APH), the densities of ground-nesting birds and rodents are positively associated due to predator-prey dynamics and prey-switching. However, it remains unclear how the strength of these predator-mediated interactions change along a climatic harshness gradient in comparison with the effects of climatic variation. We built a hierarchical Bayesian model to estimate the sensitivity of ptarmigan populations to interannual variation in climate and rodent occurrence across Norway during 2007–2017. Ptarmigan abundance was positively linked with rodent occurrence, consistent with the APH. Moreover, we found that rodent dynamics had stronger effects on ptarmigan in colder regions. Our study highlights how species interactions play an important role for the population dynamics of species at higher latitudes and suggests that they can become even more important in the most climatically harsh regions.

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