Does size matter? A bioeconomic perspective on optimal harvesting when price is size-dependent

Body size is a key parameter influencing demographic characteristics of fish populations as well as market value of landed catch. Yet in bioeconomic modelling, body size is often an overlooked biological and economic parameter. Here we evaluate how size-dependent pricing influences optimal harvest strategies in a model parameterized for two pelagic fisheries, those targeting Atlantic herring ( Clupea harengus ) and Atlantic mackerel ( Scomber scombrus ), in Norway. In our model, positively size-dependent pricing clearly shifts optimal harvest strategies towards lower harvest rates and higher mean body size of caught fish. The results are relatively insensitive to biological (e.g., natural mortality) and economic details of the model (e.g., discount rate or demand function). These findings show that size-dependent pricing influences optimal harvest strategies aiming at maximum economic yield and, hence, requires more attention in resource economics and in fisheries management.

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A social–ecological study of stock structure and fleet dynamics in the Newfoundland herring fishery

ICES Journal of Marine Science ◽

10.1093/icesjms/fsx097 ◽

2017 ◽

Vol 75 (1) ◽

pp. 257-269 ◽

Cited By ~ 2

Author(s):

Barbara Paterson ◽

Barbara Neis ◽

Robert L Stephenson

Keyword(s):

Ecological Study ◽

Social Dynamics ◽

Clupea Harengus ◽

Stock Structure ◽

Atlantic Mackerel ◽

Social Ecological ◽

Fishing Strategies ◽

Stock Assessments ◽

Fleet Dynamics ◽

Pelagic Fisheries

Abstract Successful management of small pelagic fisheries is critical in integrated ecosystem based approaches and requires understanding of how the ecological dynamics of pelagic stocks mesh with the economic and social dynamics of commercial fisheries and the larger systems within which they operate. Combining insights from stock assessments with those from local fishers, scientists, and managers, can help identify knowledge gaps that could jeopardize stock resilience. This article presents results from a social-ecological, mixed-methods study that combines insights from science and from interviews with fishermen, scientists, and managers of small pelagic fisheries in western Newfoundland, Canada (NAFO division 4R) and in NAFO division 4X. Different approaches to herring management are used in the two areas. In area 4R fishing for herring (Clupea harengus) is part of a complex multi-species, multi-gear fishery; most harvesters who target herring also target Atlantic mackerel (Scomber scombrus). Harvester interviews indicate herring in 4R, like herring in 4X and elsewhere, have substantial within-species stock structure, but that it is not well-documented in science and not well protected under the current management system. Further, fishing strategies in the competitive mackerel fishery in which the herring vessels are involved may contribute to the risk of over-fishing on some herring populations.

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Fecundity in the hermaphroditic land snail Succinea putris (Pulmonata: Succineidae): does body size matter?

Journal of Molluscan Studies ◽

10.1093/mollus/eyq026 ◽

2010 ◽

Vol 76 (4) ◽

pp. 376-383 ◽

Cited By ~ 4

Author(s):

L. Dillen ◽

K. Jordaens ◽

L. De Bruyn ◽

T. Backeljau

Keyword(s):

Body Size ◽

Land Snail ◽

Size Matter

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Body size-dependent Cd accumulation in the zebra mussel Dreissena polymorpha from different routes

Chemosphere ◽

10.1016/j.chemosphere.2016.10.128 ◽

2017 ◽

Vol 168 ◽

pp. 825-831 ◽

Cited By ~ 11

Author(s):

Wen-Li Tang ◽

Douglas Evans ◽

Lisa Kraemer ◽

Huan Zhong

Keyword(s):

Body Size ◽

Zebra Mussel ◽

Dreissena Polymorpha ◽

Cd Accumulation ◽

Size Dependent

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An ecological explanation for hyperallometric scaling of reproduction

10.1101/2021.03.12.435090 ◽

2021 ◽

Author(s):

Tomos Potter ◽

Anja Felmy

Keyword(s):

Body Size ◽

Reproductive Output ◽

Resource Competition ◽

Natural Populations ◽

Scaling Exponent ◽

Wild Populations ◽

Wet Season ◽

Size Dependent ◽

In The Wild ◽

The Relationship

AbstractIn wild populations, large individuals have disproportionately higher reproductive output than smaller individuals. We suggest an ecological explanation for this observation: asymmetry within populations in rates of resource assimilation, where greater assimilation causes both increased reproduction and body size. We assessed how the relationship between size and reproduction differs between wild and lab-reared Trinidadian guppies. We show that (i) reproduction increased disproportionately with body size in the wild but not in the lab, where effects of resource competition were eliminated; (ii) in the wild, the scaling exponent was greatest during the wet season, when resource competition is strongest; and (iii) detection of hyperallometric scaling of reproduction is inevitable if individual differences in assimilation are ignored. We propose that variation among individuals in assimilation – caused by size-dependent resource competition, niche expansion, and chance – can explain patterns of hyperallometric scaling of reproduction in natural populations.

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Negative body size‐dependent resource allocation underlies conspicuous sexual ornaments in a territorial damselfly

Journal of Evolutionary Biology ◽

10.1111/jeb.13963 ◽

2021 ◽

Author(s):

Mingzi Xu ◽

Ola M. Fincke

Keyword(s):

Resource Allocation ◽

Body Size ◽

Sexual Ornaments ◽

Size Dependent

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Evaluation of species distribution forecasts: a potential predictive tool for reducing incidental catch in pelagic fisheries

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2016-0274 ◽

2017 ◽

Vol 74 (11) ◽

pp. 1717-1731 ◽

Cited By ~ 3

Author(s):

Sara M. Turner ◽

Jonathan A. Hare ◽

John P. Manderson ◽

David E. Richardson ◽

John J. Hoey

Keyword(s):

Species Distribution ◽

Species Distribution Models ◽

Forecast Model ◽

Clupea Harengus ◽

Distribution Models ◽

Predictive Tool ◽

Atlantic Mackerel ◽

Alosa Aestivalis ◽

Incidental Catch ◽

Oceanographic Conditions

Nontarget catch restrictions are becoming common in fisheries management. We test a potential tool for reducing nontargeted catch that combines species’ distribution models and ocean forecast models. We evaluated our approach for Atlantic herring (Clupea harengus), Atlantic mackerel (Scomber scombrus), alewife (Alosa pseudoharengus), and blueback herring (Alosa aestivalis). Catch of the latter two species is capped in commercial fisheries of the former two species. Ocean forecasts were derived from a data-assimilative ocean forecast model that predicts conditions 0–2 days into the future. Observed oceanographic conditions were derived from CTD casts and observed fish presence–absence was derived from fishery-independent bottom trawl collections. Species distribution models were used to predict presence–absence based on observed and forecasted oceanographic conditions, and predictions for both were very similar. Thus, most of the error in predicted distributions was generated by the species distribution models, not the oceanographic forecast model. Understanding how predictions based on forecasted conditions compare with predictions from observed conditions is key to developing an incidental catch forecast tool to help industry reduce nontarget catches.

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Optimal Harvesting for Size-Dependent Control

Vietnam Journal of Mathematics ◽

10.1007/s10013-019-00370-6 ◽

2019 ◽

Vol 47 (4) ◽

pp. 881-895

Author(s):

Sebastian Aniţa ◽

Ana-Maria Moşneagu

Keyword(s):

Optimal Harvesting ◽

Size Dependent

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Size-dependent seasonal activity for males of the dung beetle Copris acutidens (Coleoptera: Scarabaeidae)

The Canadian Entomologist ◽

10.4039/tce.2019.55 ◽

2019 ◽

Vol 151 (6) ◽

pp. 757-767 ◽

Cited By ~ 1

Author(s):

Mayumi Akamine

Keyword(s):

Body Size ◽

Sex Ratio ◽

Dung Beetle ◽

Threshold Value ◽

Reproductive Period ◽

Seasonal Activity ◽

Size Dependent ◽

Horn Length ◽

Female Bias ◽

Early Activity

AbstractThis study aimed to determine differences in activities between two male morphs of the dung beetle Copris acutidens Motschulsky (Coleoptera: Scarabaeidae) during the reproductive period and to examine the size distribution of reproductive males that stayed in nests. The activities of two male morphs distinguished by a threshold value of body size were compared with those by horn length. Regardless of body size or horn length, earlier activity of minor males was observed during the reproductive period. The sex ratio showed the greatest female bias when minor males were the more abundant than major males, indicating that minor males were the most active when competition was the weakest and these could avoid direct combat with major males. In morphs distinguished by horn length, more major males than minor males stayed in nests with females although the major males became the most active from the middle of the reproductive period. Thus, longer horns may directly confer a competitive advantage to males, enabling them to stay in nests with females, whereas early activity of minor males does not always indicate the effect of horn length directly. Therefore, this behaviour may occur regardless of whether the morphs differ in body size or horn length.

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Perch Selection by Three Cooccurring Species ofCelithemis(Odonata: Libellulidae): Testing for a Competitive Hierarchy among Similar Species

Psyche A Journal of Entomology ◽

10.1155/2016/9028105 ◽

2016 ◽

Vol 2016 ◽

pp. 1-8 ◽

Cited By ~ 3

Author(s):

Wade B. Worthen ◽

Parker H. Morrow

Keyword(s):

Body Size ◽

Niche Partitioning ◽

Open Water ◽

The Other ◽

Similar Species ◽

Male Body ◽

Size Dependent ◽

Anatomical Characters ◽

Relative Abundances ◽

Imagej Software

In many communities of perching dragonflies (Odonata: Libellulidae), a size-dependent competitive hierarchy creates a positive relationship between male body size and perch height. We tested for this pattern among three similar-sized species:Celithemis elisa,C. fasciata, andC. ornata.Males were caught and photographed from May to July 2015 at Ashmore Heritage Preserve, Greenville County, SC, USA, and perch heights and perch distance to open water were measured. Five indices of body size were measured with ImageJ software: abdomen length, forewing length, hindwing length, area of forewing, and area of hindwing.Celithemis fasciatawas significantly larger than the other two species for all five anatomical characters and used perches that were significantly taller and closer to open water than the other species, though these differences changed over the summer. Aggressive interactions between and within species were tallied and compared to expected distributions based on mean relative abundances derived from hourly abundance counts. Patterns of interspecific aggression were also consistent with a size-dependent hierarchy: the largeC. fasciatawas attacked less frequently, and the smallC. ornatamore frequently, than predicted by their relative abundances. We conclude that even small differences in body size may contribute to niche partitioning in perch selection.

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