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- 1. A visual assessment method, called Discrete Group Censusing, was used to assess and monitor five coral reef fish assemblages in the Key Largo National Marine Sanctuary, Florida, USA.
- 2. Samples were obtained quarterly from Winter 1988 to Autumn 1990 to investigate a possible relation between the variability of reef fish assemblages and human disturbance.
- 3. Two types of disturbance were studied: a ship grounding that occurred 4 years previous to the study, and intensive, recreational snorkel and SCUBA diving. These disturbances appeared to have no short-term effect on the temporal variability of the reef fish assemblages during the study period.
- 4. Furthermore, the assemblages at all five study sites appeared to be extremely stable over the 2 year period of the study. These results support the theory that coral reef fish assemblages are highly ordered and stable over relatively large spatial scales.
- 5. The Discrete Group Censusing visual assessment method was found to be a valuable and easily applied tool for the nondestructive in situ monitoring of reef fish assemblages on coral reefs.
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- 1. The legislation of the Great Lakes jurisdictions dealing with control of exotic species introduced through ballast water, canals, and recreational boating was analysed to determine whether the USA and Canada have the capacity to manage nuisance exotic species effectively. Despite the deleterious ecological effects attributed to exotic aquatic species, there is a lack of complementary legislation between Canada and the USA to remedy this problem. Current legislation is fragmented at the bilateral, national, and the state/provincial level.
- 2. American legislative initiatives are far ahead of Canada's, especially for regulating ballast water in oceanic shipping. Canada lacks strong federal and provincial legislation to regulate ballast water in shipping and to prevent the secondary spread of exotic aquatic species through watersheds.
- 3. Legislation to regulate ballast water is developing quickly among the US federal government and the Great Lakes states. However, legislation affecting the spread of exotic nuisance species via canals and recreational boaters is needed to complement ballast water laws and to give agencies a broader mandate for management.
- 4. Amendment of the Boundary Waters Treaty Act, the Fisheries Act, and the Canada Water Act could give the Canadian federal government authority to regulate ballast water in vessels entering the St Lawrence and to begin the rehabilitation of aquatic habitats impaired by nuisance exotic species.
- 5. Preventing further species introduction and spread through the Great Lakes basin requires restricting certain shipping and boating practices. This can be achieved only by the enactment of complementary laws among all the American and Canadian jurisdictions.
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- 1. Recreational power boating is growing in popularity in North America. This activity is known to have lethal and sub‐lethal effects on aquatic wildlife and freshwater turtles may be particularly sensitive to this activity.
- 2. This study reports on patterns of traumatic injuries inflicted by powerboat propellers to northern map turtles (Graptemys geographica) from two sites differing in boat traffic intensity in Ontario, Canada.
- 3. The relative vulnerability of turtles was assessed, in light of seasonal patterns in boat traffic, as a function of sex‐ and age‐specific movement patterns, habitat use, and basking behaviour obtained by radio‐telemetry. Population viability analyses (PVA) were also conducted to evaluate the potential demographic consequences of mortality induced by powerboats.
- 4. The prevalence of propeller injuries was two to nine times higher in adult females than in adult males and juvenile females. Patterns of movement, habitat use, and aquatic basking indicated that adult females are more exposed to collisions with boats. PVA showed that boat‐induced mortality in adult females could lead to rapid population extinction if the risk of mortality when hit by a boat is greater than 10%.
- 5. The results of this study showed that recreational power boating is a serious threat to northern map turtles, even under moderate boat traffic. The need to adopt measures restricting boat traffic in areas important to turtles is discussed. Copyright © 2009 John Wiley & Sons, Ltd.
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Karolina Bacela‐Spychalska Michal Grabowski Tomasz Rewicz Alicja Konopacka Remi Wattier 《水产资源保护:海洋与淡水生态系统》2013,23(4):606-618
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- Understanding how different forms of environmental evidence inform the actions of different stakeholders is useful to improve how we share knowledge with knowledge users. Reflections on a literature review that we published in 2004 on circle hooks as a tool for fish conservation in the recreational fishing sector identified a number of ways in which that synthesis was influential.
- The article has had direct influence on policy and regulations in a number of countries, but there were even more examples of where the article has been used to influence voluntary guidelines. The article also contributed to formally defining circle hooks, which was necessary from a regulatory and enforcement perspective.
- The recreational fishing community has also embraced the work, with numerous angling articles based on the literature review appearing in the media and with some angler organizations pushing for the adoption of circle hooks. The fishing tackle industry has also responded with evidence that circle hooks are now more widely available in stores with more hook design options to suit diverse recreational fisheries. In addition, the influence of the article has extended beyond the recreational sector to commercial fishery issues that span several taxa. The research agenda from the article helped to direct research for more than a decade and has since been updated.
- Overall, this review was timely in that it provided various knowledge users with credible information synthesized in a thoughtful manner at a time when there was interest and need in exploring circle hooks as a tool to enhance the conservation of angled fish. Although this was not a systematic review, it still served as a form of evidence synthesis that gave diverse knowledge users information to guide them in their decisions.
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- 1. 309 Great Barrier Reef Marine Park recreational fishers were surveyed to examine recreational catch and harvest of elasmobranchs and to explore recreational fishers' handling behaviour and attitudes.
- 2. Elasmobranchs represented 6% of fishers' total catch of all fish (including released individuals), and 0.8% of fishers' total harvest (i.e. retained individuals) across all survey days. The majority of elasmobranchs caught by fishers were released, primarily because they were perceived as being inedible.
- 3. Recreational fishers' self‐reported handling and release behaviour for elasmobranchs is largely consistent with ‘best practice’ guidelines except that fishers had low use of circle hooks and barbless hooks, and a significant proportion (33%) reported using stainless steel hooks.
- 4. Most fishers had positive attitudes towards elasmobranchs, placing high importance on releasing sharks and rays in good condition (86%), high value on their existence (84%), and low value on catching them (63%).
- 5. Results indicate that post‐release mortality is probably the largest source of recreational fishing mortality of elasmobranchs in the Great Barrier Reef. Future research should be targeted at obtaining better estimates of species‐specific post‐release mortality levels, understanding how post‐release survival can be increased by changing fishing techniques or fisher behaviour, and developing more effective methods of engaging fishers in elasmobranch conservation. Copyright © 2009 John Wiley & Sons, Ltd.
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- 1. In 2006, two periods of hypoxia resulted in the death of approximately 35 tonnes of black bream (Acanthopagrus butcheri) in Lake Indoon, a small inland lake in Western Australia.
- 2. Acanthopagrus butcheri was the first fish species to be recorded in this lake, along with the mosquitofish (Gambusia holbrooki) which was also observed during sampling in 2006. Acanthopagrus butcheri appears to have been introduced to Lake Indoon between 1998 and 2003 and formed a self‐sustaining population. It is believed to have been deliberately introduced for the purpose of creating a recreational fishery, despite the existence of substantial penalties for illegal translocation of fish in Western Australia.
- 3. Recent human‐induced environmental changes, including rising groundwater and salinization, have probably aided the establishment of both species in Lake Indoon. The importance of salinity to recruitment success by A. butcheri was indicated by the presence of only two age classes in 2006, with estimated recruitment dates coinciding with the years of highest recorded salinity in the lake.
- 4. The ‘fish kills’ provided an opportunity to examine aspects of A. butcheri biology in a relatively low salinity environment which is atypical for this estuarine species. In particular, the recruitment period in Lake Indoon was delayed until autumn/winter, rather than spring/summer as seen in other populations. Biological responses in Lake Indoon have implications for natural populations living in estuaries with modified salinity regimes.
- 5. The ecological, social and economic impacts potentially arising from the introduction of fish to Lake Indoon, which is an important migratory bird habitat and a recreational amenity for local residents and tourists, illustrate the complexities of fish translocation and the need for rigorous assessment before stocking to identify potential costs and benefits.
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Integrating fishing and conservation in a risk framework: A stochastic population model to guide the proactive management of a threatened freshwater crayfish 
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下载免费PDF全文 Charles R. Todd Nick Whiterod Scott M.C. Raymond Sylvia Zukowski Martin Asmus Macgregor J. Todd 《水产资源保护:海洋与淡水生态系统》2018,28(4):954-968
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Tim R. McClanahan Nyawira A. Muthiga Joseph Maina Albogast T. Kamukuru Saleh A.S. Yahya 《水产资源保护:海洋与淡水生态系统》2009,19(7):758-771
- 1. Surveys of coral reefs in northern Tanzania were conducted in 2004/5 with the aim of comparing them over an～8‐year period during a time of increased efforts at fisheries management and the 1998 El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) coral mortality event that caused 45% mortality in northern Tanzania and much of the Indian Ocean.
- 2. Changes associated with both management, its absence, and the ENSO were found but changes were generally small and ecological measures indicated stability or improvements over this period, particularly when compared with reports from much of the northern Indian Ocean.
- 3. Fisheries management in two areas increased the biomass of fish and benthic communities. A small fisheries closure (0.3 km2) displayed little change in the coral community but ecological conditions declined as measured by sea urchins and fish abundances. This change may be associated with its small size because similar changes were not measured in the large closure (28 km2).
- 4. The few sites without any increased management were still degraded and one site had experienced a population explosion of a pest sea urchin, Echinometra mathaei.
- 5. The lack of significant changes across this disturbance indicates that these reefs are moderately resilient to climate change and, therefore, a high priority for future conservation actions.
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- 1. The lagoon fishery of Rodrigues has considerable socio‐economic importance; however, catches have declined by 50% in recent years. The bluespine unicornfish, Naso unicornis (Forsskål 1775) is an important component of the fishery.
- 2. To begin to assess whether marine reserves might benefit this species, sonic telemetry was used to track individual fish in one of Rodrigues' four marine reserves. Seven unicornfish were caught in the Grand Bassin reserve and tagged with abdominally implanted acoustic tags.
- 3. Over a period of 57 days their locations were determined up to 21 times using a hand held hydrophone and receiver. Individual minimum convex polygon (MCP) home ranges varied from ～10 000 m2 to ～274 000 m2 and were not correlated with fish size. Kernel estimates of core areas (50% utilization distribution) varied from ～5000 m2 to ～175 000 m2. All seven fish stayed within the marine reserve and the largest home range occupied less than ～2% of the area of the marine reserve.
- 4. Fish remained on the outside edge of the lagoon on the shallow reef slope and among coral patches. These findings suggest that bluespined unicornfish biomass and numbers should increase if the Grand Bassin marine reserve is closed to fishing. Long‐term monitoring will, however, be required to demonstrate this outcome. Copyright © 2010 John Wiley & Sons, Ltd.
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- 1. Marine reserves can play an important role in the conservation of subpopulations of marine fish metapopulations. The population spatial structure of northern Atlantic cod of Newfoundland and Labrador has characteristics of a metapopulation. Subpopulations of northern Atlantic cod on the continental shelf were decimated by decades of overfishing, and have not recovered. The remaining northern cod are concentrated in coastal areas.
- 2. A Marine Protected Area (MPA) was established in Gilbert Bay, Labrador by the Government of Canada in 2005 to protect the bay's resident subpopulation of northern Atlantic cod. Conservation of Gilbert Bay cod will help protect the genetic diversity of the northern cod metapopulation.
- 3. Unlike some other MPAs, Gilbert Bay is not a harvest refugium or ‘no‐take’ reserve. Aboriginal subsistence fisheries for salmonids with a bycatch of cod are allowed in designated areas of the MPA. A recreational fishery for Atlantic cod by angling open to all people is under consideration. Management of the MPA must ensure that fishing activities do not endanger the local cod population.
- 4. The population dynamics of Gilbert Bay cod were simulated using an age‐structured Leslie matrix model to estimate the total mortality under various recreational fishing scenarios. The level of sustainable harvest by a recreational fishery depends on the natural mortality of the Gilbert Bay cod population, which is unknown. Therefore, there is risk in permitting a recreational fishery in the MPA.
- 5. There may be benefits to the northern cod metapopulation, if the Gilbert Bay subpopulation is allowed to rebuild to the carrying capacity of the bay. If the abundance of Gilbert Bay cod exceeds the level which the local marine ecosystem can support, some cod may emigrate from the bay and recolonize adjacent coastal areas. The potential for Gilbert Bay cod to recolonize continental shelf areas is less certain.
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- Fisheries monitoring is essential to evaluate and manage fish populations. Effective monitoring is particularly challenging in low- and middle-income countries where fisheries often occur at large spatial scales and include multiple techniques. Recreational spearfishing, for instance, can be detrimental to fish populations and is often underrepresented in management strategies due to the lack of data.
- Because recreational fishers frequently share pictures of their catches online, social media can harbour valuable information. As a case study, freely available pictures in social media were used to assess the impacts of spearfishing on the endemic and endangered Brazilian parrotfish, Scarus trispinosus, that has experienced a sharp population decline in recent decades due to overfishing.
- It was found that S. trispinosus is widely captured by recreational spearfishing and at larger sizes when compared to artisanal fisheries, revealing complementary fishing pressures operating on different life stages of this species and a lack of compliance to current regulations. The number of users sharing these contents increased between 2007 and 2018, but declined thereafter until 2020.
- Identifying where spearfishing is more intense and the most targeted life-stages can inform prioritization of management strategies. Social media can be a rapid and low-cost tool to obtain nationwide fisheries information, especially for recreational fishing activities that have a flawed monitoring.
- The public disclosure of ‘trophy fishes’ can reveal lack of compliance to existing regulations and help fill critical information gaps on complementary fishing pressures. This approach may be applicable for many species and types of trophy fishing, providing valuable and useful information for management and conservation.
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R.J. Davidson 《水产资源保护:海洋与淡水生态系统》2001,11(6):417-435
- 1 With the establishment of the 619‐ha Long Island—Kokomohua Marine Reserve in April 1993, a biological monitoring programme designed to investigate changes due to the total no‐take legislation applied to the reserve was initiated.
- 2 Size, distribution and behaviour of blue cod (Parapercis colias; Pinguipedidae) were investigated using baited hooks at reserve and control rubble bottom habitats annually from 1993 to 2000. Blue cod abundance was estimated using visual diver strip transects annually for a period of 9 years from 1992 to 2001.
- 3 A total of 5628 blue cod (2436 reserve and 3192 control specimens) were captured, measured and released. Two years after the reserve was established, the average size of blue cod was 22.4 mm larger inside the reserve compared with control sites outside it.
- 4 Over the duration of the study, the mean length of blue cod captured using baited hooks increased in the no‐take reserve, but declined at the control sites. By the end of the study, in April 2000, the proportion of large blue cod >330 mm in length in the reserve was 35% compared with <1% at the control sites, where recreational fishing activities occurred.
- 5 Blue cod catch rates from experimental fishing in the reserve increased within 11 months of removal of recreational fishing activities and continued to increase up to 47 months, in contrast to the control areas where recreational fishing was permitted, catch rates remained consistently low. Increased catch rates in the reserve were not due to increased blue cod abundance, rather an increase in the proportion of naïve fish in the population.
- 6 From March 1998 to the end of the study, the density of blue cod in the reserve was significantly higher compared with the control sites. This increase was primarily due to an increase in the density of larger blue cod >300 mm length in the reserve and a corresponding small decline in the density of these larger fish at the control sites.
- 7 It is concluded that the cessation of recreational fishing in the reserve had resulted in an increase in blue cod size, catch rate and abundance and also in a change to blue cod behaviour.