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1.
《African Journal of Marine Science》2013,35(4):491-500
Illegal fishing activities are reported to be on the increase in South Africa, including in its marine protected areas (MPAs). Research is presented on the nature and the scale of illegal fishing in Table Mountain National Park (TMNP) by analysing the numbers of abalone Haliotis midae and West Coast rock lobster Jasus lalandii confiscated from fishers operating in the park's marine protected area between 2000 and 2009. Data were collected from offence logbooks maintained by South African National Parks rangers and managers, the South African Police Services, and interviews with alleged or self-confessed illegal fishers. The research findings indicate that the annual numbers of illegally fished abalone and rock lobsters have increased significantly over time. Spatial analysis suggests that confiscations of abalone occur predominantly on the east coast of the park, whereas higher confiscations of illegally fished rock lobsters occur on the west coast. It is clear from this research that new and more efficient approaches will need to be designed and implemented to minimise illegal fishing in the TMNP MPA. Context-specific conservation targets that acknowledge and integrate social as well as developmental needs are required, and may be essential for limiting biodiversity loss in the longer term, which will ultimately ensure the success of fisheries management and conservation in TMNP. 相似文献
2.
The absence of properly identified mechanisms to adequately protect the marine environment remains a major shortcoming in Australia’s commitment to biodiversity conservation. The current commitment to a National Representative System of Marine Protected Areas (NRSMPA) falls far short of providing adequate protection against the suite of existing and potential threats even though areas are designated as being ‘protected’. In this paper it is argued that the actions taken under the NRSMPA are disproportionately concentrated on regulating fishing, including the closing of areas in so-called sanctuary zones to all types of fishing. In the absence of clearly identified threats from most forms of fishing and without assessment of how best to manage those few fishing threats that have been identified, such actions are inefficient and mostly inappropriate. Moreover, they do not provide adequate protection against the full suite of threats to marine environments. Adequate measures for the proper conservation of these areas and/or the protection of marine biodiversity more generally are not being provided and in most cases threats are not even adequately described and evaluated. 相似文献
3.
The introduction of marine protected areas (MPAs) in Australia has resulted in an increase in the number and total area of ‘no-take’ zones. The resulting closures impact all forms of commercial and recreational fishing in and around them despite international recognition indicating that Australian fisheries were already well managed according to ecological sustainable development guidelines. Furthermore, it is recognised within Australia that most MPAs are not designed to provide protection from the full suite of known threats that can affect biodiversity and long-term ecosystem viability. By directing MPA management disproportionately towards comprehensive no-take zones that affect fishing practices that are already required by state and federal legislation to adhere to sustainability requirements, the suite of threats affecting both protected and unprotected areas can be left inadequately and/or inappropriately managed. It is shown in this paper that the modified definition of the Precautionary Principle, which was developed specifically for the MPA process in Australia, is not in keeping with accepted international definitions and guidelines for the use of precaution. It is argued that the development of a definition of precaution to justify a predetermined output (MPAs) devalues the sound use of scientific principles and diminishes the conservation outcome. Furthermore, by distracting efforts from determining and managing the full suite of recognised threats, the value of what protection is provided in Australia's marine protected areas is eroded further. 相似文献
4.
Man-made defence structures (e.g., breakwaters, jetties) are becoming common features of marine coastal landscapes all around the world. The ecology of assemblages of species associated with such artificial structures is, however, poorly known. In this study, we evaluated the density and size of fish predators of echinoids (i.e., Diplodus sargus, Diplodus vulgaris, Sparus aurata), and the density of sea urchins (i.e., Paracentrotus lividus) at defence structures (i.e., breakwaters) inside and outside the marine protected area of Miramare (northern Adriatic Sea) in order to: (1) assess possible differences in fish predator density and size between protected and fished breakwaters; (2) assess whether fish predation may have the potential to affect sea urchin density in artificial rocky habitats. Surveys were carried out at four random times over a period of two years. Total density, and density of medium- and large-sized individuals of the three predatory fishes were generally greater at the protected than at the fished breakwaters, whereas no differences were detected in the density of small-sized individuals. Density of the sea urchin P. lividus did not show any difference between protected and fished breakwaters. The results of this study suggest that: (1) protection may significantly affect predatory fishes in artificial rocky habitats; (2) differences in predatory fish density, and size may be unrelated with the density of the sea urchin P. lividus; (3) protected artificial structures such as breakwaters, originally planned for other purposes, could represent a potential tool for fish population recovery and enhancement of local fisheries. 相似文献
5.
《Marine Policy》2014
Long-standing concerns about the effects of scallop dredging and demersal trawling on high diversity mudstone reef and cobble habitats in Lyme Bay, southwest England, were addressed by the exclusion of bottom towed fishing gear from a 206 km2 area in July 2008. A consortium led by Plymouth University Marine Institute was funded by the UK Department of Environment, Food and Rural Affairs to design and implement a study (initially funded for 3 years) to examine the effects of the closure on both nekton and epibenthos. This paper provides a detailed account of the methodology employed from survey design to data analysis to provide a protocol for future MPA monitoring programmes. Information on historical fishing effort, substrate distributions and current and previous closure boundaries was overlaid using GIS to locate suitable monitoring sites. Non-destructive and cost-effective techniques, including a towed high-definition video array and static baited video, were used to quantify changes in relative abundances of epibenthos and nekton over three years at sites previously fished but now closed to bottom towed fishing compared to both fished and un-fished reference sites. The monitoring programme as described provides a model for robust, cost-effective evaluation of the efficacy of policy instruments for feedback into the adaptive management cycle. 相似文献
6.
Malcolm R. Clark Ashley A. Rowden 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(9):1540-1554
Seamounts, knolls, pinnacles and other “seamount-like” features are prominent and widely distributed features of the New Zealand marine environment, and also the focus of important commercial fisheries and some exploratory mineral mining. There is considerable debate about the effects of such activities on the benthic habitat of deep-water seamounts. In 2001 a study was undertaken of eight seamount-features on the Chatham Rise, an area that has been heavily trawled for orange roughy since the early 1990s. Half of the study seamounts were considered unfished and the other half fished. Benthic macro-invertebrate assemblages of each seamount were sampled using epibenthic sleds, whilst the presence of habitat-forming fauna (e.g., live corals), substrate type and indications of trawling (e.g., trawl door marks) were determined using a towed underwater camera. Fisheries catch-effort data were examined to determine the amount and distribution of bottom trawling effort on the seamounts. Analyses of camera data revealed that unfished seamounts possessed a relatively large amount of stony coral habitat comprising live Solenosmilia variabilis and Madrepora oculata (predominantly on the seamount peaks) whereas fished seamounts had relatively little coral habitat. Indications of trawling were observed over six times more frequently on seabed images from fished as opposed to unfished seamounts, and appeared related to the amount of fishing effort on individual seamounts. Multivariate analyses of sled data revealed a significant difference in macro-invertebrate assemblage composition between fished and unfished seamounts. The variability observed in assemblage composition between seamounts can in part be explained by the relative fishing pressure measured by a fishing effects index. The results of the study are discussed with respect to management of seamount habitat, and the need for ongoing monitoring and research to derive conservation practices that allow for sustainable seamount fisheries. 相似文献
7.
《Marine Policy》2014
Managing small-scale fisheries in a developing country like the Philippines is very challenging because of high pressures from expanding fishing population, poverty and lack of alternative options. Thus, resource-focused fisheries management initiatives such as marine protected area (MPA) establishment will likely result in further marginalization of the poor fishers which could pose more serious problems in coastal communities. In this study, the status of small-scale fisheries in 44 coastal towns in the Philippines was assessed using FISHDA (Fishing Industries' Support in Handling Decisions Application), a simple decision support tool which requires minimal or easily-generated data. Results showed that 68% (30 out of 44) of the studied towns have unsustainable fisheries unless 58% of their fishing grounds are protected from all fishing activities. Alternatively, 53% of the active fishers in towns with unsustainable fisheries must totally stop fishing to avert fishery collapse. Alarming as it may sound, this is still an underestimate as catches incurred by the highly efficient and destructive illegal fishing activities such as blast, poison and large-scale fishing, which are reported to be still rampant in many coastal areas in the Philippines, were not accounted for in this study. This study demonstrated that MPAs alone may not be enough to avert fishery collapse even if MPA size is increased from the current 3% to 15% of the municipal waters, i.e. up to 15 km from the shore, as required by the Philippine law. Various challenges confronting the fishery and important recommendations to address them are further discussed. 相似文献
8.
One of the aims of Mediterranean marine protected areas (MPAs) is to increase populations of exploited species, such as the European spiny lobster (Palinurus elephas), which is considered a key species for its commercial and ecological value. Monitoring of temporal patterns in abundance of early benthic stages of P. elephas indicated that predation may be higher inside the Medes Islands MPA relative to adjacent control sites. Tethering experiments were performed to test whether predation rates actually differed within and outside the MPA. Relative mortality of recently‐settled juveniles inside the MPA was much higher than in control sites in adjacent non‐protected areas. Treatments with and without shelter indicated that predation on recently‐settled juvenile spiny lobsters was moderated by the availability of suitable shelter. The decline or absence of fish predators in the fished area may be the reason why juvenile lobsters outside the MPA experience lower predation than within the MPA. 相似文献
9.
《Marine Policy》2014
This study aims to evaluate the effectiveness of currently available substrate data to designate marine reserves to meet conservation objectives. The case study site is Lyme Bay (approx. 2460 km2), in the western English Channel. An area of 240 km2 in Lyme Bay was designated ‘closed to bottom dredging’ in July 2008 with the aim of protecting reefs which are an important habitat for Eunicella verrucosa (pink sea fan). The effects of using different substrate data resolution on the selection of sites to protect a range of biotopes using the Marxan package are determined. The effect of including a closed area on the efficiency of a marine reserve network is also investigated. Findings suggest that substrate data did not capture the biodiversity of the area and that using no data at all was equally effective. If low resolution data are all that are available then other options, such as expert opinion, or other data, such as activity use information could be used instead. Including a predefined closed area into the analysis led to an increase in area required to meet conservation goals using high resolution biotope data. It also increased the area of the reserve using the three substrate layers with no increase in protection for biotopes. This suggests that when designing networks of marine protected area sites, including current protected areas may be inefficient, resulting in larger areas being protected with no increased conservation of marine biodiversity. Policy makers must be prepared to adapt management in light of these findings and be aware of the shortcomings of the data available for use in marine conservation planning. 相似文献
10.
Tag reporting rate is an important parameter required for estimating fishing and natural mortality in fished populations. It is an extremely difficult parameter to estimate and can vary both during the fishing season and between fishing years. Improving tag reporting rates has been identified as a cost‐effective way of improving precision in fishing and natural mortality estimates derived from tagging data. In this study we evaluated the use of passive integrated transponder (PIT) tags to improve tag reporting rates in a lobster (Jasus edwardsii) trap fishery. To minimise the risk of PIT tag ingestion by consumers, we tested insertion of the PIT tag into the base of the antennae, the base of the walking leg, and the base of the telson. The base of the antennae proved to be the best option for lobster health although impacts were observed at all tag insertion sites. We further developed and tested a hybrid tag that combined a conventional external T‐bar tag with a PIT tag embedded within the shaft. PIT tag scanners were positioned in bottlenecks in the capture process so that all lobsters retained on board the vessel were passed through a scanner. Thus, the tag reporting rate was expected to be 100% for the subsample of the fleet fitted with scanners when scanners were operational. Scanner malfunction was a major issue and further engineering solutions are required to ensure that scanners are reliable when working in harsh marine conditions such as on‐board fishing vessels. Advantages of the hybrid tag are: the ability to be detected by both automatic detectors and fishers; known tag‐induced mortality and tag loss rates from previous research; and PIT tagging without risk of human ingestion. 相似文献
11.
12.
Abstract This study provides a first evaluation of the biological impact of a marine fishery reserve on the stock of queen conch (Strombus gigas) in the Turks and Caicos Islands. The density and the shell length of the population living in the reserve are compared with those of the individuals living in the surrounding fished areas. The results show that the adult density is six times higher in the reserve than in the fished areas. The shell length analysis shows that both adults and juveniles are significantly smaller in the reserve than in the fished area. This unexpected result suggests the existence of a crowding effect (i. e. a high density‐induced reduction in growth rate) within the reserve. It is hypothesised that this crowding effect is due to the superimposition of two factors leading to very high density values in the reserve: (a) the reduced fishing mortality following the creation of the reserve, (b) the existence of natural barriers that impede the emigration of adults outside the reserve. These results are then discussed in relation to current considerations on marine fisheries reserves. 相似文献
13.
In order to enable effective management of marine protected areas (MPAs), desired MPA achievements need to be identified as early as possible for the development of relevant and clear management goals, objectives and conservation targets. As the definition of MPA success is a social construct, the involvement of multiple groups in this process including government agencies, stakeholders, and other interested parties is increasingly advocated. This study investigates diverse groups’ opinions on the performance of a proposed National Marine Conservation Area (NMCA) on the West coast of Canada prior to its establishment. In order to analyse and quantify the importance of MPA performance criteria among multiple stakeholder groups, the Analytical Hierarchy Process (AHP) is applied. Findings reveal that marine stakeholder groups have distinct preferences for future MPA performance. Most differences are obvious between user and non-user groups. The study also finds that respondents’ characteristics other than stakeholder groups affiliations influence expectations towards the proposed MPA including livelihood dependency on the marine environment, amount of time spent in the area, and engagement in fishing activities. 相似文献
14.
On 1 December 2007, eight ‘Small Island Developing States’ in the Western and Central Pacific Ocean implemented a management regime restricting the total number of days fished by tuna purse seine vessels within their waters, commonly referred to as the Vessel Day Scheme (VDS). The VDS is seen as one component of management arrangements to reduce fishing mortality on bigeye and yellowfin tuna, constrain fishing effort, and increase the rate of return from access fees by Distant Water Fishing Nations. 相似文献
15.
Large intensity and diversity of human activities result in an increase in complexity in the utilization of space. This paper describes the fisheries and a method to map fishing efforts and catches of different fleets by combining vessel monitoring system (VMS) data and logbook data. The method makes it possible to explore the spatial and temporal variability of fishing and the potential impacts of proposed management measures on the fisheries. The method is proposed to be used in the development of management plans for marine protected areas such as Natura 2000 sites, designated to protect vulnerable habitats and species. 相似文献
16.
不同环境因子权重对东海鲐鱼栖息地模型的影响研究 总被引：4，自引：1，他引：3
鲐鱼（Scomber japonicus）是栖息在西太平洋沿岸的中上层鱼类,了解其栖息地分布及其与海洋环境因子的关系有助于合理开发和管理该资源。本文根据2003-2011年7-9月中国东海鲐鱼的生产数据,采用正态分布函数分别构建海表面温度（sea surface temperature,SST）、海表温梯度（gradient of sea surface temperature,GSST）和海表面高度（sea surface height,SSH）与作业次数的适应性指数（suitability index,SI）,基于不同权重的算术平均法（arithmetic weighted model,AWM）分别建立栖息地指数（habitat suitability index,HSI）模型,并用2012年7-9月生产数据进行验证。结果显示,7、8、9月各月最佳HSI模型的SST、STG和SSH的权重分别为0.5、0.25、0.25,0.8、0.1、0.1和0、1.0、0,利用2012年7-9月生产数据与环境数据对各月份最佳权重HSI模型进行验证,在HSI>0.6的海域,7、8、9月各月作业次数比重和产量比重分别为85.87%和92.55%,76.74%和86.69%,51.83%和56.11%。研究表明,不同月份的环境因子对鲐鱼渔场分布的影响程度不同,本研究为更好地预测鲐鱼栖息地奠定了基础。 相似文献
17.
《Marine Policy》2016
Temporary marine area closures or more permanent Marine Protected Areas are being proposed as potential options in ecosystem-based marine spatial management. These policy options are known to displace fishing effort. In this paper, EU Vessel Monitoring System (VMS) data is combined with other site and vessel information and used to model the fishing site choice decision of Irish demersal otter trawlers. Uniquely, the fishing ground options used in the analysis reflect the actual seabed contours trawled by the fleet. The fishing site choice model, based on this natural site definition is compared to an alternative destination choice model where the fleet decision is specified using a grid based site definition as employed in previous work. It is argued that the natural site specification is a more realistic specification of the fisher site choice decision. Using the preferred natural fishing site choice model, a policy scenario involving the hypothetical closure of one of the fishing ground options is then simulated to examine the possible redistribution of fishing effort. 相似文献
18.
《Journal of Sea Research》2000,43(2):167-176
The use of shell damage records as an in situ indicator of past fishing disturbance was investigated using the dog cockle Glycymeris glycymeris L. Shell sections of dog cockles collected from four areas subjected to varying levels of fishing disturbance were examined for the presence of damage records or shell ‘scars’. Animals from a heavily fished area had significantly higher levels of scarring than those from three lightly fished areas. From an estimation of the age of the shells (from internal growth lines and dating of each line), the year in which scarring occurred was determined and this was compared to yearly records of fishing effort. There was a weak but significant positive correlation between the frequency of shell scars per year and the intensity of fishing effort. Our data suggest that whilst scarring in shells of G. glycymeris cannot accurately be used to estimate past fishing intensity on a year-by-year basis, it can be used to differentiate between severely impacted and lightly fished areas of the sea bed. 相似文献
19.
In this paper, two benthic habitats have been investigated in a fully protected site and two control sites at the Tavolara-Punta Coda Cavallo marine protected area (MPA) (NE Sardinia). Overall, a protection effect on the benthic assemblages was highlighted in the shallow subtidal (5 m deep) rather than at intertidal algal turf habitat. Structure of assemblages at the shallow subtidal habitat is different in the fully protected site vs. controls, while this was not true for the intertidal habitat. At the subtidal, this finding is probably linked to indirect effects due to an increase of consumers in the protected site (e.g., sea urchins), while the lack of direct impacts in the intertidal at control sites is indicative of very similar assemblages. Cover of encrusting algae was significantly higher at the subtidal protected site suggesting a possible higher grazing pressure. Possible causes underlying the inconsistency of results obtained between habitats include the possibility that trophic cascade effects have a different influence at different heights on the shore. The need to estimate the interconnection among benthic habitats through trophic links is also highlighted to provide an estimate of the vulnerability to protection of various habitats. 相似文献
20.
自20世纪80年代以来,我国出台了众多海洋捕捞相关政策,厘清这些政策变迁规律对海洋捕捞业的健康发展具有重要意义。本文对1986年以来我国海洋捕捞业的政策文本展开量化分析,构建政策时间维度、政策工具维度、政策价值维度三维政策文本分析框架,梳理当前捕捞业政策变迁和结构特征,并深入分析了捕捞业政策与现实的匹配性。研究发现,海洋捕捞业的部分政策目标之间存在一定的冲突和矛盾;政策工具体系全面,但不同政策工具数量分布不均衡;早期政策的经济价值取向突出,社会、生态价值相对不足,需要适时调整政策价值取向。未来应明确政策目标,推动海洋捕捞管理范式由投入控制向产出控制的转变;优化政策工具组合,引导渔民自觉养护海洋渔业资源,提高海洋捕捞业政策的有效性;整合政策价值取向,协调产业发展、资源养护和渔民利益的关系,推动海洋捕捞可持续发展。 相似文献