Where do we draw the line? A simulation approach for evaluating management of marine fish stocks with isolation-by-distance stock structure

2015 ◽  
Vol 72 (7) ◽  
pp. 968-982 ◽  
Author(s):  
Ingrid Spies ◽  
Paul D. Spencer ◽  
André E. Punt
Keyword(s):  
Marine Fish ◽  
Isolation By Distance ◽  
Management Strategies ◽  
Marine Species ◽  
Fishing Effort ◽  
Stock Structure ◽  
Pacific Cod ◽  
Entire Area ◽  
Lower Productivity ◽  
Management Protocol

There is no established management protocol for stocks subject to isolation-by-distance (IBD) stock structure. This study examines several management strategies for two marine fish species subject to IBD using simulation: Pacific cod (Gadus macrocephalus) in the Aleutian Islands (AI) and northern rockfish (Sebastes polyspinis) in the Eastern Bering Sea (EBS) and AI. A one-dimensional stepping stone model was used to model IBD and was intended to mimic regions where marine species are exploited along a continental shelf. The performance of spatial assessment and management methods depended on how the range was split. Splitting anywhere within the managed area led to fewer demes falling below target and threshold biomass levels and higher yield than managing the entire area as a single unit. Equilibrium yield was maximized when each deme was assessed and managed separately and under catch cascading, in which harvest quotas within a management unit are spatially allocated based upon the distribution of survey biomass. The longer-lived rockfish declined more slowly than Pacific cod and experienced greater depletion in biomass under disproportionate fishing effort because of lower productivity. Overall, splitting a management area of the size simulated in the model improved performance measures, and the optimal management strategy grouped management units by demes with similar relative fishing effort.

Biological reference points for sea scallops (Placopecten magellanicus): the benefits and costs of being nearly sessile

2004 ◽  
Vol 61 (8) ◽  
pp. 1338-1354 ◽  
Author(s):  
Stephen J Smith ◽  
Paul Rago
Keyword(s):  
Management Strategies ◽  
Fishing Effort ◽  
Reference Points ◽  
Placopecten Magellanicus ◽  
Nonlinear Mixed Effects Models ◽  
Lower Productivity ◽  
Boom And Bust ◽  
Sea Scallops ◽  
Habitat Damage ◽  
Definition Of

In this paper, we concentrate on spatial aspects of growth and reproduction for sea scallops (Placopecten magellanicus) to advance the general theory for development of reference points for sessile animals and to illustrate the general points with several specific examples. Nonlinear mixed effects models can be used to define the spatial distribution of growth rates and their implications for the definition of growth overfishing. We develop a basin model to illustrate that the typical "boom and bust" effects, often attributed to environmental factors, are explained equally well by spatial variations in habitat quality, spatial concentration of fisheries, and dispersal of larvae among areas. Results suggest that incentives to concentrate fishing effort in lower productivity areas may be an effective tool for reducing recruitment variation and improving yields. Reductions in fishing mortality might be possible with closed areas as they can be used to reduce the concentration of effort on high scallop densities. Further, rotational area management strategies can offer the promise of balancing demands for increased yield, prevention of recruitment overfishing, maintaining spawning reserves, and reducing habitat damage and bycatch.

Stock structure of Lethrinus laticaudis (Lethrinidae) across northern Australia determined using genetics, otolith microchemistry and parasite assemblage composition

2018 ◽  
Vol 69 (4) ◽  
pp. 487 ◽  
Author(s):  
Diane P. Barton ◽  
Laura Taillebois ◽  
Jonathan Taylor ◽  
David A. Crook ◽  
Thor Saunders ◽  
...  
Keyword(s):  
Isolation By Distance ◽  
Spatial Scales ◽  
Distance Effect ◽  
Fishing Effort ◽  
Northern Territory ◽  
Otolith Microchemistry ◽  
Stock Structure ◽  
Northern Australia ◽  
Complementary Techniques ◽  
Population Genetic Analyses

The grass emperor Lethrinus laticaudis is a conspicuous element of the commercial and recreational catch from nearshore reef systems across northern Australia. The nearshore reef systems across northern Australia are exposed to increasing levels of fishing pressure from commercial and recreational fishers. To inform ongoing management of this species, the present study examined the stock structure of L. laticaudis across northern Australia using a combination of complementary techniques. In all, 342 L. laticaudis samples were collected from 13 locations in the coastal waters of northern Australia ranging from the Pilbara region of Western Australia to Moreton Bay in south-east Queensland. Population genetic analyses using microsatellite markers demonstrated that there were at least four genetically distinct populations across northern Australia with gene flow between management jurisdictions (with significantly more separation between Western Australian and Northern Territory locations than between Northern Territory and Queensland locations). An isolation by distance effect was evident (genetic differences increasing linearly with distance). Otolith microchemistry and parasitology analyses indicated some spatial structuring of populations within broader regions. These findings of restricted connectivity at small spatial scales suggest that L. laticaudis is vulnerable to localised depletion in areas where fishing effort is concentrated. This conclusion is consistent with recent observations of fishery declines in heavily fished locations.

The utility of genetics in marine fisheries management: a simulation study based on Pacific cod off Alaska

2015 ◽  
Vol 72 (9) ◽  
pp. 1415-1432 ◽  
Author(s):  
Ingrid Spies ◽  
André E. Punt
Keyword(s):  
Population Dynamics ◽  
Genetic Testing ◽  
Marine Fish ◽  
Fish Species ◽  
Error Rates ◽  
Reference Points ◽  
Marine Fish Species ◽  
Pacific Cod ◽  
Management Units ◽  
Entire Area

Information on genetic population structure has been documented in many marine fish species, but it is not always incorporated into management plans. This study examines how conservation status and yield change when management units are established using genetic data versus treating the entire area as a single management unit. Simulations use a spatially structured, individual-based model that combines multilocus microsatellite genotypes and a traditional fish population dynamics model that establishes abundance-at-age by cohort. Results are considered in terms of marine fish species in general, and parameters in the model are based on Pacific cod (Gadus macrocephalus) in the Bering Sea and Aleutian Islands region of Alaska. Population dynamics are projected under several management strategies, some of which establish management units based on the results of genetic testing and some that do not. Simulations incorporate annual stock assessments and fishing for 100 years. Results show that managed fishing can result in a reduction in stock sizes below target reference points when distinct populations are not managed based on the results of genetic testing. However, stock size is maintained at target levels and catches may increase when stocks identified using genetics are managed separately, even given error rates inherent to genetic testing.

Studi pengembangan unit perbenihan ikan laut di Pulau Gumilamo Kabupaten Halmahera Utara

2015 ◽  
Vol 3 (3) ◽  
Author(s):  
Yitzhak Koloba ◽  
Hengky J Sinjal ◽  
Ockstan Kalesaran
Keyword(s):  
Local Government ◽  
Development Strategy ◽  
Marine Fish ◽  
Government Regulation ◽  
Swot Analysis ◽  
Fishing Effort ◽  
Government Support ◽  
Fish Hatchery ◽  
The Development Strategy ◽  
Internal And External Factors

This research intended  to evaluate the development strategy of Marine Fish Hatchery Unit at Gumilamo Island, North Halmahera. Analysis SWOT was used to determine the development strategy. Data were collected by questionnaire, interview and literature relevant to the research. SWOT analysis showed the internal and external factors that affected the development of Marine Fish Hatchery at Gumilamo island. The strenght were location, water quality , local government support, and availability of seeds and feed. Weakness were lack of public interest, lack of extension and human resources. Opportunity were the high value of the sale, business opportunities and  local government regulation. Treat were  dependence on fishing effort and safety.   Keywords : hatchery, gumilamo, north halmahera, SWOT analysis

scholarly journals Management of Ankle Fractures with Syndesmotic Disruption: A Survey of Orthopaedic Surgeons

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0040
Author(s):  
Ryan G. Rogero ◽  
Emmanuel M. Illical ◽  
Daniel Corr ◽  
Steven M. Raikin ◽  
James Krieg ◽  
...  
Keyword(s):  
Gold Standard ◽  
Ankle Fracture ◽  
Management Strategies ◽  
Ankle Fractures ◽  
Multinomial Regression ◽  
Orthopaedic Surgeons ◽  
Suture Button ◽  
Standard Management ◽  
Management Protocol ◽  
Usage Patterns

Category: Ankle; Trauma Introduction/Purpose: With an increasing frequency of syndesmotic fixation during ankle fracture ORIF and no current gold standard management protocol, it is important for surgeons to understand the frequency and usage patterns of the various techniques among other orthopaedic surgeons. The purposes of this study are to determine how orthopaedic surgeons currently manage ankle fractures with concomitant syndesmotic disruption and to identify surgeon demographics predictive of syndesmotic management. Methods: An 18-question survey, including 10 specific syndesmotic management questions was sent to the Orthopaedic Trauma Association (OTA) and Canadian Orthopaedic Association (COA), as well as sent to email addresses of foot and ankle-fellowship trained surgeons. Surgeon demographic questions included years, country, and type of practice, fellowship(s) completed, setting of ankle fracture surgery, and number of ankle fractures operated on per year. Multinomial regression analysis was performed to determine if surgeon demographics were predictive of syndesmotic management. Results: One-hundred ten orthopaedic surgeons completed our survey. Selected predictors of syndesmotic management included: private practice with academic appointments (0.077 [0.007, 0.834]; p=0.035) being predictive of not using screws through an ORIF plate; foot & ankle fellowship (9.981 [1.787, 55.764]; p=0.009) and trauma fellowship (6.644 [1.302, 33.916]; p=0.023) predictive of utilizing screws through a plate; no fellowship (14.886 [1.226, 180.695]; p=0.034) predictive of only using 1 screw; and surgeons practicing in the U.S. were more likely to not use screws across just 3 cortices (0.031 [0.810, 3.660]; p=0.009). Additionally, among those utilizing suture-button devices, foot & ankle fellowship-trained surgeons were more likely to implement suture-button through plate (7.676 [1.286, 45.806]; p=0.025). Conclusion: Several surgeon factors influence decision making in the management of ankle fractures with syndesmotic disruption. This study raises awareness of differences in management strategies that should be used for further discussion when determining a potential gold standard for management of these complex injuries.

Genetic isolation by distance and localized fjord population structure in Pacific cod (Gadus macrocephalus): limited effective dispersal in the northeastern Pacific Ocean

2009 ◽  
Vol 66 (1) ◽  
pp. 153-166 ◽  
Author(s):  
Kathryn Maja Cunningham ◽  
Michael Francis Canino ◽  
Ingrid Brigette Spies ◽  
Lorenz Hauser
Keyword(s):  
Population Structure ◽  
Pacific Ocean ◽  
Isolation By Distance ◽  
Spatial Scales ◽  
Puget Sound ◽  
Pacific Cod ◽  
Genetic Population ◽  
Pacific Cod Gadus Macrocephalus ◽  
Gadus Macrocephalus ◽  
Northeastern Pacific

Genetic population structure of Pacific cod, Gadus macrocephalus , was examined across much of its northeastern Pacific range by screening variation at 11 microsatellite DNA loci. Estimates of FST (0.005 ± 0.002) and RST (0.010 ± 0.003) over all samples suggested that effective dispersal is limited among populations. Genetic divergence was highly correlated with geographic distance in an isolation-by-distance (IBD) pattern along the entire coastal continuum in the northeastern Pacific Ocean (~4000 km; r2 = 0.83), extending from Washington State to the Aleutian Islands, and over smaller geographic distances for three locations in Alaska (~1700 km; r2 = 0.56). Slopes of IBD regressions suggested average dispersal distance between birth and reproduction of less than 30 km. Exceptions to this pattern were found in samples taken from fjord environments in the Georgia Basin (the Strait of Georgia (Canada) and Puget Sound (USA)), where populations were differentiated from coastal cod. Our results showed population structure at spatial scales relevant to fisheries management, both caused by limited dispersal along the coast and by sharp barriers to migration isolating smaller stocks in coastal fjord environments.

scholarly journals Functional genetic diversity in an exploited marine species and its relevance to fisheries management

2021 ◽  
Vol 288 (1945) ◽  
pp. 20202398
Author(s):  
Eleni L. Petrou ◽  
Angela P. Fuentes-Pardo ◽  
Luke A. Rogers ◽  
Melissa Orobko ◽  
Carolyn Tarpey ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Isolation By Distance ◽  
Chromosomal Rearrangements ◽  
High Mobility ◽  
Marine Species ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Reproductive Timing ◽  
Cultural Significance ◽  
Ecological Processes

The timing of reproduction influences key evolutionary and ecological processes in wild populations. Variation in reproductive timing may be an especially important evolutionary driver in the marine environment, where the high mobility of many species and few physical barriers to migration provide limited opportunities for spatial divergence to arise. Using genomic data collected from spawning aggregations of Pacific herring ( Clupea pallasii ) across 1600 km of coastline, we show that reproductive timing drives population structure in these pelagic fish. Within a specific spawning season, we observed isolation by distance, indicating that gene flow is also geographically limited over our study area. These results emphasize the importance of considering both seasonal and spatial variation in spawning when delineating management units for herring. On several chromosomes, we detected linkage disequilibrium extending over multiple Mb, suggesting the presence of chromosomal rearrangements. Spawning phenology was highly correlated with polymorphisms in several genes, in particular SYNE2 , which influences the development of retinal photoreceptors in vertebrates. SYNE2 is probably within a chromosomal rearrangement in Pacific herring and is also associated with spawn timing in Atlantic herring ( Clupea harengus ). The observed genetic diversity probably underlies resource waves provided by spawning herring. Given the ecological, economic and cultural significance of herring, our results support that conserving intraspecific genetic diversity is important for maintaining current and future ecosystem processes.

scholarly journals An Inverted Management Strategy for the Fishery of Endangered Marine Species

2021 ◽  
Vol 8 ◽  
Author(s):  
Hudson T. Pinheiro ◽  
Jose A. C. C. Nunes ◽  
E. O. C. Coni ◽  
E. C. G. Almeida ◽  
C. L. S. Sampaio ◽  
...  
Keyword(s):  
Endangered Species ◽  
Management Strategy ◽  
Management Strategies ◽  
Marine Species ◽  
Management Plan ◽  
Brazilian Coast ◽  
Innovative Strategy ◽  
Key Species ◽  
The Government ◽  
Marine Areas

Overfishing is notorious for triggering population collapses and disrupting marine biological functioning worldwide. To counter such a threat, policy-makers have created and implemented multiple management strategies, but most were incapable to prevent the decline of several key species. Here, we discuss a new management strategy in force since June 2019 in Brazil that aims to deter the overfishing of parrotfish species of the genera Scarus and Sparisoma. This innovative strategy, here referred to as inverted management, allows the capture of endangered parrotfish species inside management areas, such as partially protected marine areas—MPAs, but bans it elsewhere. This initiative is supposed to be built in a partnership among the government, scientists, managers, and fishers. If implemented correctly, endangered species would recover in the much larger area outside MPAs, and fishers would benefit from the conservation-value of the scarce and valued product. However, to succeed, the strategy depends on the adoption of a series of challenging management rules that are not currently being enforced along an extensive coastline. So far, few MPAs have incorporated rules for endangered species in their management plan, and those that have done so have no plans or the means to enforce them. Therefore, fishing of endangered species is currently ongoing without any management or monitoring in the entire Brazilian coast. Concerned with the challenges to develop plans to recover populations of endangered species faced by Brazilian managers, we suggest wide communication and a ban on the fisheries until management plans are implemented. Additionally, we suggest that the effectiveness of the inverted management strategy for parrotfishes should be assessed before it’s applied to other endangered species.

scholarly journals First two bilateral hand transplantations in India (Part 3): Rehabilitation and immediate outcome

2017 ◽  
Vol 50 (02) ◽  
pp. 161-167
Author(s):  
Mohit Sharma ◽  
Subramania Iyer ◽  
P. Kishore ◽  
Jimmy Mathew ◽  
Sundeep Vijayaraghavan ◽  
...  
Keyword(s):  
Management Strategies ◽  
Standard Of Care ◽  
Daily Basis ◽  
Substantial Improvement ◽  
Outcome Analysis ◽  
Functional Magnetic Resonance ◽  
Experimental Procedure ◽  
Management Protocol ◽  
Second Dual

ABSTRACT Introduction: This report covers the strategies adopted for rehabilitation for the first and second dual hand transplants performed in India. Materials and Methods: The team, under a trained physiatrist, including physiotherapy and occupational therapy personnel, was involved in the management of both these patients. The management protocol was developed considering previous reports as well as our management strategies in the rehabilitation of the replanted hands. The involvement of the team with the patients started in the 1st week itself and continued on a daily basis for the entire year. Results: Outcome analysis was performed at 6 months and 1 year using the disability of shoulder and hand evaluation and hand transplant scoring system. Functional magnetic resonance imaging was done at the end of 1 year to assess the cortical integration of the transplanted hand. Conclusion: Despite more than 110 hands being transplanted worldwide, hand transplant remains an experimental procedure. It is still not considered the “standard of care” for hand amputees. Outcome analyses performed worldwide do indicate that the procedure can provide a substantial improvement in the quality of life for the hand amputee, especially the bilateral amputees.

Sign in / Sign up

Export Citation Format

Share Document