Size Limit Regulations Research Articles

Application of the Method Evaluation and Risk Assessment Tool for a Small-Scale Grouper Fishery in Indonesia

Management strategy evaluation using the Method Evaluation and Risk Assessment (MERA) platform was used to evaluate management procedures (MPs) for improving the management of the leopard coral grouper (Plectropomus leopardus) fishery in Saleh Bay, Indonesia. This grouper is a valuable species currently under high fishing pressure. It is targeted by small-scale fisheries using a wide range of fishing methods; hence, management recommendations are needed to ensure sustainability. A suite of MPs for data-limited conditions were evaluated for their ability to achieve limit and target biomass reference points (B/BMSY = 0.5 and B/BMSY = 1, respectively), while maintaining a target yield of at least 0.5 MSY. The simulation results suggest that the currently implemented harvest control rules (HCRs) in Saleh Bay (size limit and spatial closure) may not be effective in achieving the management objective to attain the target biomass reference point due to relatively low compliance with the size limit regulation (320 mm total length) and the very small proportion of existing MPA no-take areas (~2.2%). This study recommends that the fisheries management authority explores the feasibility of implementing the total allowable catch (TAC) and seasonal closure in addition to the existing fishing regulations for P. leopardus in Saleh Bay.

Scraping and grazing herbivorous/detritivorous fish display opposite feeding behaviours under different protection regulations

ABSTRACT Herbivorous and detritivorous fish display complex feeding behaviour, and research into how feeding behaviour changes with environmental and social variables is lacking. Such knowledge is imperative to infer how herbivory/detritivory will differ, in light of shifting resources and communities and specifically whether reefs can recover from disturbance. Fish abundance, feeding rate, body size, diet and schooling feeding of three major functional groups (scrapers, grazers and browsers) were examined across reef types under different fishing regulations. Scrapers and grazers (parrotfishes and surgeonfishes) were more abundant and displayed the highest feeding rates on reef flats. Scrapers mainly resided inside the restricted zone, while more grazers were found in the general use zone, where macroalgal abundance was highest. Browsers (rabbitfishes) were seldom observed and patchily gathered on the reef flat and reef slope in both zones. Thus, fishing protection did not appear to benefit grazers and browsers, whereas more scrapers gathered on shallow reef flats in the protection zone. Scraper and grazer feeding rates increased from an individual to a pair and increased with body size, these factors led to variations in feeding behaviours across reef types and protection regulations. Protection appears to benefit scrapers and variations in feeding rates were largely related to school size. Lastly, grazer density was associated more with macroalgal coverage than protection status. The opposite feeding behaviours of scrapers and grazers indicates not only protection status, but fishing restrictions and size limit regulations are needed to maintain coral reef fisheries and functional diversity on coral reefs in Taiwan.

Population Dynamic Parameters for Cyprinus carpio in Dianshan lake

Data from lake Dianshan for Cyprinus carpio were collected from January to December 2013. This study provides the first results on fishery dynamics of the species in this Lake and is aimed at estimating important population dynamic parameters and assessing the stock of this economically important fish species by the help of length frequency data collected. FiSAT II software was used for different analyses. The mean fork length analyzed was 24.14 cm, lengths ranged from 5.5 to 69 cm, the dominant length group ranged from 14 to 16.9 cm (16.9%). The length weight relationship parameters were (Wt = 0.054(FL)2.75), r2 = 0.84, and condition factor K = 3.17. The parameters of von Bertalanffy growth curve were L∞ = 74.55 cm, K = 0.2, to = − 0.33 and o = 3.17. The estimated values of the total, natural and fishing mortalities were Z = 0.67, M = 0.37, F = 0.30 respectively. The current exploitation rate of the species was calculated as 0.45 which was lower than the maximum allowable exploitation rate obtained as 0.484, indicating they are almost fully exploited However, regular monitoring programs should be implemented for the sustainability of these resources and an immediate action such as size-limit regulation by gradually increasing fishing gears mesh size will be necessary for a sustainable exploitation of this fishery.

Embracing uncertainty, continual spawning, estimation of the stock–recruit steepness, and size-limit designs with length–based per-recruit analyses for African tropical fisheries

Per-recruit analysts of African tropical fish mostly applied deterministic and sex-aggregated length–based Beverton–Holt per-recruit models, but rarely examined the spawning biomass per-recruit (SBPR), spawning potential ratio (SPR), size-limit regulations, and stock–recruit steepness (h). To relax the restrictive assumptions of the previous models, this study outlines a framework of using length–based per-recruit models accounting for continual spawning and incorporating uncertainty in sex-specific and total yield per-recruit (YPR), SPR, h, equilibrium yield (Ye), and biological reference points, especially those based on fishing mortality, F (FBRPs). Continual spawning is incorporated through weighting SBPR with monthly proportions of the spawning-capable stage. Uncertainty is introduced into life-history parameters through the resampling with replacement and with bivariate normal distributions, and into various metrics through Monte Carlo simulations. The Beverton–Holt and Ricker stock–recruit relationships are assumed in yield functions. The approach is illustrated with the Bukabuka (Lates stappersii Boulenger, 1914) fishery in southern Lake Tanganyika, for which the potential effects of alternative minimum length limits (Lmin) and catch-and-release values on various metrics are examined. Females Bukabuka represent 63% of the combined YPR and SBPR because they predominate in large sizes; h is greater if recruitment were dependent on both sexes than on females; the most imprecise metrics are the YPR, Ye, and MSY benchmarks; cryptic mortalities of sublegal individuals would exacerbate growth-overfishing; higher Lmin and discard survivals would lead to higher FBRPs, but can prevent recruitment-overfishing; in the F–Lmin planes, the contours maximizing YPR and Ye can be the basis for optimal Lmin designs. Strategies most likely to benefit the Bukabuka fishery would apply Lmin=250–300mm fork length and promote full compliance with releases and ways to reduce post-discard mortality.

Growth, Mortality Parameters and Exploitation Rate of West African Ilisha (<i>Ilisha africana</i> Bloch, 1795, Clupeidae) off Benin Coastal Waters (West Africa): Implications for Management and Conservation

West African Ilisha was the third most abundant species of Clupeidae off Benin coastal waters after Sardinella spp and Ethmalosa frimbriata. The fishing effort of these fisheries increased with a dominance of small-sized specimens in the catches. This paper allowed updating some demographic parameters and the exploitation rate of Ilisha africana collected between July 2013 and June 2014 from the coastal waters of Benin for management and conservation of these fisheries. The growth pattern showed a negative allometric growth with an abundance of small-sized specimens. The von Bertalanffy growth function (VBGF) estimations were: L∞= 21.31 cm standard length; K = 1.20 year-1; and t0 = -0.138 year. The total mortality rate (Z), natural mortality rate (M) and fishing mortality rate (F) were 4.040 year-1, 2.27 year-1 and 1.77 year-1 respectively. The Z/K ratio was 3.667 and the exploitation rate (E = F/Z) was 0.44 showing an under exploitation of this species. The estimated potential longevity (tmax) was 2.5 years. In addition, the fisheries management should be devolved from the state to the local level to compel fishermen to take greater responsibility for the sustainability and conservation of the fisheries such as size-limit regulation by gradually increasing fishing gears mesh size.

Commercial harvest and export of snapping turtles (Chelydra serpentina) in the United States: trends and the efficacy of size limits at reducing harvest

As Asian turtle populations have crashed, China has increasingly turned to international import to meet domestic demand, which has increased pressure on global turtle populations. Snapping turtles (Chelydra serpentina) are being harvested in unprecedented numbers in the United States (US) to meet the needs of this international market. Here we report US snapping turtle live export from 1999 to 2013, and for the first time test the effectiveness of size limits in reducing commercial harvest numbers. Over three million live snapping turtles from farm and wild caught stock were exported from the US to Asia in 2012–14 alone. Increases in the export of wild caught snapping turtles to over 200,000 individuals in 2012 and 2014, compared to under 50,000 in other years, may indicate that farms are becoming unable to keep up with increasing demand. Annual harvest pressure at the state level increased linearly from 1998 to 2013, mirroring trends in federal export over the same time period. Our model estimates that size-limits were effective at reducing harvest by 30–87% in years with high harvest pressure. However, the majority of size limit regulations result in the removal of larger breeding adults, which has been shown to be detrimental to long term population viability. Regulatory approaches dedicated to the long term management of this iconic species will need to balance the short term gains, in the form of reduced harvest rates, with long term population viability.

Obelix vs. Asterix: Size of US commercial banks and its regulatory challenge

Big banks pose substantial costs to society in the form of increased systemic risk and government bailouts during crises. So the question is: Should regulators limit the size of banks? To answer this question, regulators need to assess the potential costs of such regulations. If big banks enjoy substantial scale economies (i.e., average costs get lower as bank size increases), limiting the size of banks through regulations may be inefficient and likely to reduce social welfare. However, the literature offers conflicting results regarding the existence of economies of scale for the biggest US banks. We contribute to this literature using a novel approach to estimating nonparametric measures of scale economies and total factor productivity (TFP) growth. For US commercial banks, we find that around 73 % of the top one hundred banks, 98 % of medium and small banks, and seven of the top ten biggest banks by asset size exhibit substantial economies of scale. Likewise, we find that scale economies contribute positively and significantly to their TFP growth. The existence of substantial scale economies raises an important challenge for regulators to pursue size limit regulations.

Population structure and reproductive parameters of the Longneck croaker, <i>Pseudotolithus typus</i> (Pisces, Bleeker, 1863) in nearshore waters of Benin (West Africa) and their implications for management

Pseudotolithus typus is one of the two commercially important Sciaenids off Benin nearshore waters mainly fished by beach seining. Unfortunately, since 1994, the production of this species has been decreasing, and increasingly more small-sized fishes are regularly harvested, while little is known about the species’ population structure and its life history. Therefore, population structure, probability of capture and size at first capture were investigated using length-frequency data of 1144 specimens sampled from beach seine hauls over a period of 18 months. A total of 54.3% of this population was immature, confirming the domination of smallsized fishes in the catches. Gonad maturation stages were also examined. Frequency distribution of oocyte size exhibited two cohorts of mature oocytes suggesting two spawning periods per year. Monthly averages of gonado-somatic index confirmed that P. typus spawned twice a year during the major warm season (March - May) and during the transition minor warm to minor cold season in October - November. Length at first capture (L75 = 22.76 cm) was smaller than the length at first sexual maturation (L50% = 23.6 cm) indicating a heavy pressure of the beach seine on this resource. To give each fish the chance of reproducing at least once in its lifetime to recruit into the stock, necessary measures such as the size-limit regulation by gradually increasing beach seine mesh size should be developed. Community-based management of the nearshore fishery could contribute to reducing fishing effort during the reproductive periods from February to May and from October to December each year.

Effects of sexual dimorphism on population parameters and exploitation ratios of blue marlin (Makaira nigricans) in the northwest Pacific Ocean

Blue marlin are sexually dimorphic in size-at-age and other biological characteristics. However, few studies have examined the possible impact of sexual dimorphism on the population parameters and the ratios of fishing to total mortality (the exploitation ratios) for this species. We analyzed sex-specific catch-at-length data for blue marlin collected from the Taiwanese tuna longline fishery in the northwest Pacific Ocean, ranging between 100–311 cm in eye to fork length (EFL) for females and 100–236 cm EFL for males, and show that the proportion of females in the catch (the sex ratio) increases with length, with females reaching larger body sizes than males. Minor differences in fishery sex ratios among months were observed. Growth parameters, length structures, and natural mortality rates were estimated to differ between males and females, while fishing mortality rates were found to be similar. Nevertheless, the exploitation ratio for females was higher than that for males. We suggest that growth parameters and natural mortality rates should be sex-specific when assessments for sexually-dimorphic species such as blue marlin are conducted, and that management of blue marlin fisheries could be developed based on size limit regulations for large individuals.

Efficacy of harvest and minimum size limit regulations for controlling short‐term harvest in recreational fisheries

AbstractIt is important to consider the potential effectiveness of regulations for reducing total harvest levels when developing fishery management plans. A random forest (RF) modelling approach was used to examine how changing per‐angler harvest or minimum size limit regulations affected sport fishery harvest in US Atlantic coast recreational fisheries. Harvest limits per angler (i.e. bag limits) were typically high initially and subsequently reduced, whereas almost half of minimum length limits were initially below the length‐at‐maturity and subsequently increased. Across most fisheries examined, extreme reductions in harvest limits (e.g. from unlimited to catch‐and‐release) were largely ineffective at limiting total fishery harvest. Increasingly restrictive minimum length limits caused a greater average harvest reduction than per‐angler harvest limits. Some regulation changes were associated with higher angling effort and thus increased harvest, which suggests that when effort cannot be constrained, more direct harvest limitations should be considered.

Growth and mortality parameters of P. senegalensis and P. typus (Sciaenidae) in nearshore waters of Benin (West Africa) and their implications for management and conservation

Most fisheries in Africa are overexploited or are at the peak of exploitation. A key contributor to this overfishing is poor data on fisheries, inefficient management strategies and unenforced policies. Pseudotolithus species off Benin nearshore waters are mainly fished by beach seining. Unfortunately, since 1994, the production of these species has been decreasing, with more small-sized fishes appearing in catches, and little is known about the species’ population dynamics. Therefore, the growth and mortality parameters of two commercially important Sciaenids (Pseudotolithus senegalensis and Pseudotolithus typus) off Benin's nearshore waters were investigated using length–frequency data of 2019 specimens sampled from beach seine hauls over a period of 18 months. The length–weight relationship was computed from linear regression analysis. P. senegalensis exhibited isometric growth while P. typus exhibited negative allometric growth. The von Bertalanffy growth constants for P. senegalensis were TL∞=51.4cm, K=0.24yr−1, and t0=−0.60yr with a derived growth performance index of φ′=2.753. The corresponding estimates for P. typus were TL∞=56.2cm, K=0.19yr−1, t0=−0.73yr and φ′=2.652. The growth patterns determined by the growth performance index (φ′) were higher for P. senegalensis than for P. typus of similar sizes. The total mortality rate, Z, for P. senegalensis was estimated as 4.39yr−1, with the fishing mortality, F, being calculated as 3.70yr−1. The mortality estimates for P. typus were Z=4.12yr−1 and F=3.70yr−1. The exploitation rate of the two fish species was higher than the optimum exploitation criterion, which is indicative of over-fishing. Several immediate management actions, such as size-limit regulation by gradually increasing beach seine mesh size and time-limit regulation by restricting fishing outside the spawning season, are considered necessary for sustainable exploitation of these stocks.

Management of the stalked barnacle (<i>Pollicipes pollicipes</i>) fishery in the Berlengas Nature Reserve (Portugal): evaluation of bag and size limit regulation measures

SUMMARY: The stalked barnacle Pollicipes pollicipes (Gmelin, 1790) is an important shellfish resource in Portugal. Due to the social-economic importance of barnacle harvesting, a management plan aimed at achieving a controlled and sustainable activity (including temporal and spatial closures, rotational harvesting, a limited number of harvesting licenses, bag and size limits for catches and catch reporting) was implemented in 2000 at the Berlengas Nature Reserve (RNB) in central Portugal. We evaluated the bag and size limits imposed by the management plan, performing observations on harvesting activity and asking licensed harvesters and RNB staff about these measures. Both inquiries and observations suggest that licensed harvesters are not following the bag and size limits imposed. Mean amounts captured in RNB varied from 14 to 24 kg per harvester/day, but 25% of the observations corresponded to higher catches per individual than the total amount allowed (20 kg). Only half of the sampled amounts (taken in autumn 2005 and 2006) were in agreement with the size limit regulation and 50% of the total biomass comprised individuals of maximal rostro-carinal length (RC) ≥25 mm. For most harvesters, size limit is the most difficult management rule to fulfil. Both harvesters and RNB staff agree that surveillance is scarce and is a major problem of this fishing activity. In order to achieve a more sustainable use of this resource, we propose the implementation of a more effective surveillance and monitoring plan, the definition of a unique landing site, the maintenance of the bag limit (20 kg) and a reduction of the size limit (50% of total biomass comprising individuals ≥22 mm RC).

The Market Impact of Housing Size-limit Regulations in the Capital Region of South Korea

The Market Impact of Housing Size-limit Regulations in the Capital Region of South Korea

Catch-and-release and size limit regulations for blue, white, and striped marlin: the role of postrelease survival in effective policy design

Catch-and-release fishing as a management and conservation tool for billfish (family Istiophoridae) is practiced in many recreational fisheries, and mandatory release of billfish has been implemented for some commercial fisheries. Inherent in these approaches is the observation that survival of released fish is greater than those that are landed. Recent studies using pop-up satellite tags have begun to quantify postrelease survival rates for billfish, yet the efficacy of management measures that require some or all billfish to be released have not been evaluated. Using an age- and size-structured population model that accounts for individual variability in growth, we simulated the effects of postrelease mortality on yield, risk of recruitment overfishing, efficiency (i.e., ratio of harvest to postrelease mortality), and probability of catching trophy-sized individuals for three marlin species. Regulations such as size limits, catch-and-release, and mandatory release are likely to provide some benefit to billfish populations, but our results show that the effectiveness of these strategies is reduced when release survival is less than 100%. The management approaches most likely to benefit billfish populations are ones that focus on maximizing postrelease survival in the recreational fishery and minimize the billfish catch in commercial fisheries.

Characteristics of Ontario muskellunge (Esox masquinongy) fisheries based on volunteer angler diary information

This paper consolidates and summarizes information on Ontario muskellunge, Esox masquinongy, sport fisheries derived from angler diary programs sponsored by the Ontario Ministry of Natural Resources (OMNR) and Muskies Canada Incorporated (MCI) from 1979 to 2004. Interest in muskellunge as a sport fish has increased substantially over the past 10–15 years. Muskellunge catches were found to be highly correlated with angling effort. Catch rates, expressed in terms of catch-per-unit-of-effort (CUE), have improved over the past decade to the point where, in 2001, the provincial CUE was 0.119. The long term catch rate is 0.069. This improvement in angling quality is attributed to new minimum size limit regulations and increased catch-and-release angling practices. Over the period from 1979–2004, release rates by muskellunge anglers have averaged 94%. Based on a sample size of 9,499 fish, the mean size of angled muskellunge over the past 26 years was 37.0 inches (94 cm). Numerous fish exceeding 50 inches (127 cm) are angled from Ontario waters each year. The incidence of lymphosarcoma, a highly contagious, malignant blood cancer, has averaged only 2% since 1979. Based on an analysis of this information, Ontario’s muskellunge fisheries appear to be stable and sustainable. Volunteer angler diary programs provide an accurate and cost-effective means to monitor the status of muskellunge fisheries in Ontario.

Assessment of Alternative Harvest Regulations for Sustaining Recreational Fisheries: Model Development and Application to Bull Trout

Regulations designed to protect recreational fisheries from overexploitation can fail. Regulations such as size and bag limits restrict harvest by individual anglers but not angler effort and therefore not total harvest. Even when individual harvest limits are set to zero (i.e., catch and release), a combination of hooking mortality and noncompliance may lead to fishing mortality rates that are not sustainable if angling effort is sufficiently high. These assertions were tested and quantified by using simulation experiments on a size- and age-structured model developed for a fishery on an adfluvial bull trout population. The functions and rates describing the biology and fishery were derived from a variety of sources, including published and unpublished information on bull trout and, where such sources were unavailable, from other salmonid species. The model predicts that a 40-cm minimum size limit for harvest would maintain viable populations at an annual effort up to 4 angler-hours · ha−1 · year−1, a 65-cm minimum size limit up to 10 angler-hours · ha−1 · year−1, and a catch-and-release fishery up to 18 angler-hours · ha−1 · year−1. The quality of the fisheries that developed under these three alternative regulations varied substantially with the amount of angler effort imposed. Uncertainty in the minimum population size necessary to ensure sustainability, recruits per unit stock, catchability, hooking mortality rate, and noncompliance rate modifies quantitative predictions, but the qualitative patterns are general. If anglers respond dynamically to variation in the quality of fishing, then the ability of size limit regulations to sustain fisheries is further compromised. The combination of life history and fishery traits such as slow growth, late age at maturity, low fecundity, longevity, and high catchability render adfluvial bull trout particularly susceptible to overfishing, even within relatively narrow bounds of angler effort.

Effect of a Change in Fishing Regulations on the Survival and Capture Probabilities of Rainbow Trout in the Upper Rangitikei River, New Zealand

To evaluate effectiveness of a 550-mm (total length) upper size limit introduced because of concerns about the effect of increasing angling pressure, we estimated survival and capture probabilities of rainbow trout Oncorhynchus mykiss tagged in the headwaters of the Rangitikei River between March 1993 and April 1999. Estimates were obtained using simultaneous analysis of recapture data collected during tagging operations and from tag returns by anglers. We found strong evidence that fish greater than 550 mm were released at a higher rate following the introduction of the upper size limit in 1995. There was no evidence that the release rate changed during the study for fish less than 550 mm. The probability that a fish was caught by an angler during the 6-month summer period was higher than the corresponding winter period, but otherwise there appeared to be little variation through time. Neither capture nor release probabilities appeared to depend on fish sex. Larger trout had higher survival probabilities, and this relationship strengthened following the introduction of the upper size limit. Our study provides evidence that the upper size limit regulation was effective in changing both the behavior of anglers and population dynamics of the fish. This is reinforced by length-frequency data showing an increase in the average length of fish following introduction of the size-limit regulation.

An Introduction to the NMFS Marine Recreational Fisheries Statistics Survey with an Emphasis on Economic Valuation

Previous articleNext article No AccessThalassoramaAn Introduction to the NMFS Marine Recreational Fisheries Statistics Survey with an Emphasis on Economic ValuationROBERT L. HICKS, AMY B. GAUTAM, DAVID VAN VOORHEES, MAURY OSBORN, and BRAD GENTNERROBERT L. HICKS Search for more articles by this author , AMY B. GAUTAM Search for more articles by this author , DAVID VAN VOORHEES Search for more articles by this author , MAURY OSBORN Search for more articles by this author , and BRAD GENTNER Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Marine Resource Economics Volume 14, Number 4Winter 1999 Article DOIhttps://doi.org/10.1086/mre.14.4.42629280 Views: 28Total views on this site Citations: 11Citations are reported from Crossref Copyright © 2000 Marine Resource FoundationPDF download Crossref reports the following articles citing this article:Christopher M. Free, Camila Vargas Poulsen, Lyall F. Bellquist, Sophia N. Wassermann, Kiva L. Oken The CALFISH database: A century of California's non-confidential fisheries landings and participation data, Ecological Informatics 69 (Jul 2022): 101599.https://doi.org/10.1016/j.ecoinf.2022.101599Scott A. Aalbers, Michael S. Wang, Lyall Bellquist, Kate Kauer, Alexis Jackson, Chugey A. Sepulveda Characterization of a developing recreational deep-drop fishery for swordfish off southern California, California Fish and Wildlife Journal 108, no.22 (Jul 2022).https://doi.org/10.51492/cfwj.108.12William R. Andrews, Katherine J. Papacostas, John Foster A Comparison of Recall Error in Recreational Fisheries Surveys with One- and Two-Month Reference Periods, North American Journal of Fisheries Management 38, no.66 (Nov 2018): 1284–1298.https://doi.org/10.1002/nafm.10233Abigail Kaminski, Kathleen P. Bell, Caroline L. Noblet, Keith S. Evans An Economic Analysis of Coastal Beach Safety Information-Seeking Behavior, Agricultural and Resource Economics Review 46, no.22 (Jul 2017): 365–387.https://doi.org/10.1017/age.2017.17Stephen Hynes, Rainey Gaeven, Paul O'Reilly Estimating a Total Demand Function for Sea Angling Pursuits, Ecological Economics 134 (Apr 2017): 73–81.https://doi.org/10.1016/j.ecolecon.2016.12.024Ben Beardmore Boater Perceptions of Environmental Issues Affecting Lakes in Northern Wisconsin, JAWRA Journal of the American Water Resources Association 51, no.22 (Dec 2014): 537–549.https://doi.org/10.1111/jawr.12265Sergio Alvarez, Sherry L. Larkin, John C. Whitehead, Tim Haab A revealed preference approach to valuing non-market recreational fishing losses from the Deepwater Horizon oil spill, Journal of Environmental Management 145 (Dec 2014): 199–209.https://doi.org/10.1016/j.jenvman.2014.06.031B. T. van Poorten, S.P. Cox, A. B. Cooper Efficacy of harvest and minimum size limit regulations for controlling short-term harvest in recreational fisheries, Fisheries Management and Ecology 20, no.2-32-3 (Dec 2012): 258–267.https://doi.org/10.1111/j.1365-2400.2012.00872.x Timothy Haab , Robert Hicks , Kurt Schnier , and John C. Whitehead Angler Heterogeneity and the Species-Specific Demand for Marine Recreational Fishing, Marine Resource Economics 27, no.33 (Jul 2015): 229–251.https://doi.org/10.5950/0738-1360-27.3.229Paul Hindsley, Craig E. Landry, Brad Gentner Addressing onsite sampling in recreation site choice models, Journal of Environmental Economics and Management 62, no.11 (Jul 2011): 95–110.https://doi.org/10.1016/j.jeem.2010.10.007John C. Whitehead A comparison of contingent valuation method and random utility model estimates of the value of avoiding reductions in king mackerel bag limits, Applied Economics 38, no.1515 (Aug 2006): 1725–1735.https://doi.org/10.1080/00036840500427130

Comparing Minimum-Size and Slot Limits for Brook Trout Management

Abstract Consideration of reproductive, growth, and natural mortality characteristics in the design of fisheries management strategies requires adequate data and a comprehensive understanding of the influence of each factor in determining population responses to management. A review of previous management literature indicated a range of responses have been observed when size limit regulations for different species were imposed or changed. This suggests that selecting appropriate management strategies for a given set of conditions is difficult. Accordingly, strategies should be tested for efficacy before implementation. An individual-based model incorporating specific consideration of density-dependent mortality and life history characteristics was calibrated for use against available field data and used to compare random harvest and size limit management strategies for a lotic population of brook trout Salvelinus fontinalis. Results compared favorably with field-based studies of trout management strategie...

Structural Indices for Stock Assessment of and Management Recommendations for Pejerrey Odonthestes bonariensis in Argentina

Stock assessments based on catch per unit effort (CPUE), relative weight (Wr), and proportional stock density (PSD) were conducted on 18 populations of pejerrey in pampean lakes ofeastern Argentina. The CPUE ofgill nets ranged from 2.9 to 435.2 kg/net-night and was correlated with zooplankton biomass (r = 0.68; P < 0.01). The average Wr (the ratio of empirical weight to a “standard” weight for a fish of the same size, expressed as a whole number) of designated size-groups ranged from 68 to 119. Low Wr was apparent in all size-groups in two lakes with high inorganic turbidity and in one hypertrophic lake with a chlorophyll-a concentration higher than 400 μg/L. Among all the lakes, the PSD (the proportion of fish of “quality” size in a stock, expressed as a percentage) ranged from 0 to 90 and was not related to Wr of any size-group. The indices of CPUE and PSD provided useful criteria to define five types of pejerrey populations and propose minimum size or slot length limit regulations for harvest management. These evaluations and recommendations represent major challenges and opportunities for the development of fishery management plans in Argentina.