Tagging studies reveal restricted movement of snapper (Pagrus auratus) within Shark Bay, supporting fine-scale fisheries management

2012 ◽  
Vol 63 (11) ◽  
pp. 1191 ◽  
Author(s):  
Jeffrey V. Norriss ◽  
Michael Moran ◽  
Gary Jackson
Keyword(s):  
Fisheries Management ◽  
Site Fidelity ◽  
Zone Boundary ◽  
Limited Evidence ◽  
Restricted Movement ◽  
Management Zones ◽  
Shark Bay ◽  
Community Acceptance ◽  
Spawning Site ◽  
Pagrus Auratus

The snapper (Pagrus auratus) fisheries of Shark Bay’s complex inner gulfs are managed on a fine spatial scale (tens of kilometres). Following the splitting of the Western Gulf into two management zones, results from an earlier 1980s tagging study were revisited to assess the suitability of management arrangements. Recaptures up to 15 years at liberty showed highly restricted movement, with 300 of 491 occurring within 5 nautical miles of the tagging site and only 3.3% crossing the new zone boundary. A simple stock-trajectory model simulating the two Western Gulf populations demonstrated a negligible impact from a 1% per annum level of mixing. The 1980s study was repeated between 1998 and 2003 by tagging 2558 snapper, mainly in areas previously under-represented. Recaptures up to 2 years at liberty again showed highly restricted movement, with 181 of 197 recaptures occurring at the tagging site. Juveniles were more sedentary than adults, the latter showing limited evidence of inter-annual spawning-site fidelity. Together, both studies support the use of three small management zones. Community acceptance of these complex arrangements was aided by collaborating with volunteers on research programs, which improved their understanding of the population structure.

Recovery of inner Shark Bay snapper (Pagrus auratus) stocks: relevant research and adaptive recreational fisheries management in a World Heritage Property

2012 ◽  
Vol 63 (11) ◽  
pp. 1180 ◽  
Author(s):  
Gary Jackson ◽  
Michael Moran
Keyword(s):  
Fisheries Management ◽  
Threshold Level ◽  
Recreational Fishing ◽  
Minimum Length ◽  
Recreational Fisheries ◽  
Total Allowable Catch ◽  
Shark Bay ◽  
Limited Effectiveness ◽  
Pagrus Auratus ◽  
The 1960S

Despite the increasing importance of marine recreational fishing, recreational fisheries management is often hampered by lack of adequate data and limited effectiveness of conventional regulations. In Shark Bay, Western Australia, snapper (Pagrus auratus) in the Eastern Gulf, Denham Sound and Freycinet Estuary have been a major attraction for recreational fishers since the 1960s. Various management measures were progressively introduced from 1998 onwards to limit snapper catches, including increases in minimum length, introduction of a maximum length, reductions in daily bag limit, a moratorium in the Eastern Gulf (June 1998–March 2003), a 6-week spawning closure in the Freycinet Estuary and, finally, the introduction of a Total-Allowable-Catch-based system in 2003. Stock assessments in 2011 indicated that spawning biomass in the Eastern Gulf and Denham Sound had rebuilt to the management target level while biomass in the Freycinet Estuary remained below the threshold level but was continuing to slowly rebuild. This paper summarising the research and adaptive management of the snapper fishery over the last 15+ years represents an important case study that addresses a range of issues typically associated with marine recreational fisheries, including assessment of stock size and recreational catch, evaluation of management regulations and active engagement with the recreational fishing community.

A fisheries perspective of behavioural variability: differences in movement behaviour and extraction rate of an exploited sparid, snapper (Pagrus auratus)

2011 ◽  
Vol 68 (4) ◽  
pp. 632-642 ◽  
Author(s):  
Darren M. Parsons ◽  
Mark A. Morrison ◽  
Jeremy R. McKenzie ◽  
Bruce W. Hartill ◽  
Richard Bian ◽  
...  
Keyword(s):  
Population Size ◽  
Fisheries Management ◽  
Fishing Effort ◽  
Extraction Rate ◽  
Movement Behaviour ◽  
Pagrus Auratus ◽  
The Status ◽  
Likelihood Model ◽  
Lower Population ◽  
Fishery Species

Intraspecific variation in movement patterns are well established for many species, but poorly appreciated in fisheries management. In this study we dart-tagged snapper ( Pagrus auratus ), an important fishery species, across different areas and habitats in the Hauraki Gulf, New Zealand. Tag returns were used to quantify movement behaviour and extraction rates using a maximum likelihood model that corrected for spatial variability in population size and fishing effort. Residency was high (~90%) in two strata and lower (75%) in the remaining stratum. The stratum with the highest residency also appeared to experience the highest extraction rate (likely due to a lower population size). These results confirm the existence of differences in movement behaviour within the snapper population, suggesting that localized areas may become depleted regardless of the status of the overall stock. This has consequences for the scale of fisheries management and the size of marine reserves implemented in different regions. Understanding why variation in movement behaviour exists (i.e., genetic vs. environmental) is the next step in addressing the influence of animal behaviour on fisheries management.

Long-term movement patterns of continental shelf and inner gulf snapper (Pagrus auratus, Sparidae) from tagging in the Shark Bay region of Western Australia

2003 ◽  
Vol 54 (8) ◽  
pp. 913 ◽  
Author(s):  
M. Moran ◽  
C. Burton ◽  
J. Jenke
Keyword(s):  
Continental Shelf ◽  
Western Australia ◽  
Fishery Management ◽  
Target Species ◽  
Release Point ◽  
Shark Bay ◽  
Movement Characteristics ◽  
Pagrus Auratus ◽  
Low Levels

Snapper is an important commercial and recreational target species in the Shark Bay region of Western Australia. The present study aimed to define the range of movements of snapper by tagging in the two inner gulfs of Shark Bay and on oceanic fishing grounds adjacent to the Bay. Recaptures by fishers fell to low levels within 4 years after tagging, but small numbers of recaptures were still being made up to 15 years after release. There was no mixing of snapper populations between the two inner gulfs nor was there any movement between the ocean and the inner bay. This supports genetic and other evidence for the existence of several separate stocks in the region. Snapper of the ocean stock were mostly recaptured within 20 km of their release point, although a few fish moved long distances of up to 370 km southwards along the continental shelf. The tagged snapper tended to become more dispersed along the shelf with increasing years at liberty. Yet, an empirical model indicated that of the snapper recruiting to the main oceanic fishing grounds near Koks Island, which have a mean life expectancy in the fishery of 1.5 years, 76% would remain within 93 km (50 nautical miles), even after 6 years. The distinct stocks and their movement characteristics are significant for snapper fishery management in the Shark Bay region.

Complex migration routes of Atlantic bluefin tuna (Thunnus thynnus) question current population structure paradigm

2010 ◽  
Vol 67 (6) ◽  
pp. 966-976 ◽  
Author(s):  
Benjamin Galuardi ◽  
François Royer ◽  
Walt Golet ◽  
John Logan ◽  
John Neilson ◽  
...  
Keyword(s):  
Site Fidelity ◽  
Bluefin Tuna ◽  
Thunnus Thynnus ◽  
Migration Routes ◽  
Western Atlantic ◽  
Spawning Period ◽  
Atlantic Bluefin Tuna ◽  
Spawning Site ◽  
Archival Tags ◽  
Spawning Areas

Movements of Atlantic bluefin tuna ( Thunnus thynnus , ABFT) from specific western Atlantic forage grounds are not well described, and the extent of their spawning areas is mainly surmised. In 2005 and 2006, we deployed 41 pop-up satellite archival tags (PSATs) on adult Atlantic bluefin tuna off the coast of Nova Scotia, Canada, and on Georges Bank. During the assumed spawning period, 56% of the tagged ABFT occupied a known spawning area, while 44% were located in distant oceanic regions. Assuming obligate annual spawning, these results are inconsistent with the notion of spawning site fidelity to the Gulf of Mexico. The ocean-wide migrations of adult ABFT tagged on a common forage ground suggest evidence of a metapopulation requiring more spatially explicit management than the current simple two-stock structure.

scholarly journals Measuring and modelling Pacific herring spawning-site fidelity and dispersal using tag-recovery dispersal curves

2009 ◽  
Vol 66 (8) ◽  
pp. 1754-1761 ◽  
Author(s):  
Linnea A. Flostrand ◽  
Jacob F. Schweigert ◽  
Kristen S. Daniel ◽  
Jaclyn S. Cleary
Keyword(s):  
Site Fidelity ◽  
Stock Assessment ◽  
Shortest Paths ◽  
Pacific Herring ◽  
Clupea Pallasi ◽  
Rates Of Change ◽  
Spawning Site ◽  
Dispersal Curves ◽  
Dispersal Distances ◽  
Future Work

Abstract Flostrand, L. A., Schweigert, J. F., Daniel, K. S., and Cleary, J. S. 2009. Measuring and modelling Pacific herring spawning-site fidelity and dispersal using tag-recovery dispersal curves. – ICES Journal of Marine Science, 66: 1754–1761. An approach of relating Pacific herring (Clupea pallasi) tag-recovery data to dispersal distances is presented. Observations from coded wire tag sampling (1999–2006) were used to represent adult herring interannual spawning patterns on the British Columbia coast. Six datasets were applied, differing by number of years-at-liberty (1, 2, or 3) and gear type of recapture (purse-seine or gillnet). In total, 227 tag-recovery samples, consisting of 5687 tag recoveries, were used. Distances were approximated to the shortest paths through water between the release and recapture sites. Recovery rate and distance relationships suggest that exponential models fit the data reasonably well, with average rates of change in recovery rates (slopes) varying from approximately −0.009 to −0.005. A combined slope estimate of −0.007 is similar to four of the six estimates. Using these models, the intensity of movement among five stock-assessment regions was estimated by applying distances relative to their centres. Fidelity estimates range from 53 to 90% across all models and regions, which is consistent with previous findings and premises that influence resource management. Interpretation and application of the modelling exercise are discussed in terms of previous and future work.

scholarly journals Home range and elevated egg densities within an inshore spawning ground of coastal cod

2007 ◽  
Vol 64 (5) ◽  
pp. 920-928 ◽  
Author(s):  
Sigurd Heiberg Espeland ◽  
Ailin Fernløf Gundersen ◽  
Esben Moland Olsen ◽  
Halvor Knutsen ◽  
Jakob Gjøsæter ◽  
...  
Keyword(s):  
Home Range ◽  
Site Fidelity ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Generalized Additive Models ◽  
Spatial Dynamics ◽  
Additive Models ◽  
Spawning Season ◽  
Spawning Ground ◽  
Spawning Site

Abstract Espeland, S. H., Gundersen, A. F., Olsen, E. M., Knutsen, H., Gjøsæter, J., and Stenseth, N. C. 2007. Home range and elevated egg densities within an inshore spawning ground of coastal cod. – ICES Journal of Marine Science, 64: 920–928. Atlantic cod (Gadus morhua) along the Norwegian Skagerrak coast are structured into genetically distinct local populations. Mechanisms contributing to this genetic structure may include spawning site fidelity of adult cod as well as retention of pelagic early life stages close to the spawning grounds. Spawning in sheltered inshore localities is likely to favour retention of eggs and larvae, the opposite situation to offshore spawning. A combined study was made of area utilization by adult cod and the distribution of cod eggs within an inshore locality of the Norwegian Skagerrak coast. The behaviour of adult cod was studied using acoustic telemetry and kernel modelling, and eggs were sampled throughout the spawning season. Generalized additive models were applied to test hypotheses about the spatial dynamics of the eggs, and the best model described a central spawning area that retained its integrity through time. Adult cod were confined to small parts of the study area and remained there throughout the spawning season. The average home range of the adult cod was 27 ha. Overall, the study demonstrated two mechanisms by which coastal (i.e. inshore) cod maintain their population structure: spawning site fidelity and the spatial dynamics of their eggs.

scholarly journals Ultrasonic tracking reveals multiple behavioural modes of snapper (Pagrus auratus) in a temperate no-take marine reserve

2004 ◽  
Vol 61 (7) ◽  
pp. 1137-1143 ◽  
Author(s):  
D.P. Egli ◽  
R.C. Babcock
Keyword(s):  
Site Fidelity ◽  
Spatial Scales ◽  
Marine Reserve ◽  
Fish Movement ◽  
Movement Behaviour ◽  
Range Of Movement ◽  
Realistic Interaction ◽  
Pagrus Auratus ◽  
Ultrasonic Tracking ◽  
Fish Activity

Abstract Interactions between marine reserve populations and non-reserve populations of exploited fishes have generally been modelled using simplistic assumptions about behaviour. Consequently, there is a recognized need for better information on fish movement behaviour at the appropriate spatial scales to generate more realistic interaction models. Automated ultrasonic tracking of marine fish, applied in this study, offers the potential to continuously track individuals for periods of up to several years within the study area. Snapper (Pagrus auratus) (FL: 33–68 cm) were surgically implanted with individually coded ultrasonic transmitters to monitor their movement within the Cape Rodney to Okakari Point Marine Reserve in northeast New Zealand from October 2001 to September 2002. The range of movement patterns observed includes some fish resident for the entire tracking period, while others were more mobile. Of the latter group, some fish left the array permanently while others returned after up to 83 days of continuous absence. Nearly all fish showed some level of site fidelity for varying periods of the time they were tracked. Fish activity peaked in the summer, when highest densities are known to occur. Results suggest that snapper behaviour is variable, and that patterns of habitat utilization vary between fish and also seasonally. Such a complex range of behaviours may be a key component for achieving desirable outcomes for both conservation and fisheries in marine reserves.

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