scholarly journals Are depredation rates by reef sharks influenced by fisher behaviour?

2014 ◽  
Author(s):  
Magen Schifiliti ◽  
Dianne L McLean ◽  
Tim J Langlois ◽  
Matthew J Birt ◽  
Peter Barnes ◽  
...  
Keyword(s):  
Food Reward ◽  
Management Strategies ◽  
Mitigation Strategies ◽  
Recreational Fishing ◽  
Time Of Arrival ◽  
Target Species ◽  
Video Systems ◽  
Reef Sharks ◽  
Negative Impacts ◽  
Classically Conditioned

Shark depredation (damage to gear and loss of bait or hooked fish by a non-target species) is a common global occurrence. Depredation events by sharks can have negative impacts for the fishers, fishery targeted species and the sharks. It is, therefore important to better understand if learning behaviour of sharks can influence rates of depredation. Recreational fishers within the World Heritage Ningaloo Reef have reported increased rates of depredation by sharks over the last 5 years. This study aimed to determine if sharks are capable of learning to associate intensive recreational fishing activities with a food reward. We also aimed to test if sharks in areas frequently fished were more habituated to recreational fishing activities than those sharks within a no-take marine sanctuary. To simulate fishing activities baited underwater video systems were deployed in the morning (A.M.), midday, and afternoon (P.M.) for six consecutive days in Fished and Unfished sites. A significant decrease in time of arrival and time to first feed of sharks was seen across days at the Fished sites. The Unfished sites had very low numbers of sharks observed (n=3) and therefore was not statistically analysed. The relative abundance of sharks did not significantly increase across days, however there was a negative correlation between lemon sharks (Negaprion sp.) and whalers (Carcharhinus sp.). Our study suggests sharks are capable of being classically conditioned to recreational fishing activities and depredation rates are influenced by fisher behaviour. We have highlighted possible mitigation strategies designed to un-condition sharks to recreational fishing, including modifying fishing practices, use of deterrents based on the sensitivity of shark senses and management strategies. The best approach is likely to be enabling fishers to become more knowledgeable of how and why shark depredation events happen and take appropriate steps to avoid them.

scholarly journals Are depredation rates by reef sharks influenced by fisher behaviour?

2014 ◽  
Author(s):  
Magen Schifiliti ◽  
Dianne L McLean ◽  
Tim J Langlois ◽  
Matthew J Birt ◽  
Peter Barnes ◽  
...  
Keyword(s):  
Food Reward ◽  
Management Strategies ◽  
Mitigation Strategies ◽  
Recreational Fishing ◽  
Time Of Arrival ◽  
Target Species ◽  
Video Systems ◽  
Reef Sharks ◽  
Negative Impacts ◽  
Classically Conditioned

Shark depredation (damage to gear and loss of bait or hooked fish by a non-target species) is a common global occurrence. Depredation events by sharks can have negative impacts for the fishers, fishery targeted species and the sharks. It is, therefore important to better understand if learning behaviour of sharks can influence rates of depredation. Recreational fishers within the World Heritage Ningaloo Reef have reported increased rates of depredation by sharks over the last 5 years. This study aimed to determine if sharks are capable of learning to associate intensive recreational fishing activities with a food reward. We also aimed to test if sharks in areas frequently fished were more habituated to recreational fishing activities than those sharks within a no-take marine sanctuary. To simulate fishing activities baited underwater video systems were deployed in the morning (A.M.), midday, and afternoon (P.M.) for six consecutive days in Fished and Unfished sites. A significant decrease in time of arrival and time to first feed of sharks was seen across days at the Fished sites. The Unfished sites had very low numbers of sharks observed (n=3) and therefore was not statistically analysed. The relative abundance of sharks did not significantly increase across days, however there was a negative correlation between lemon sharks (Negaprion sp.) and whalers (Carcharhinus sp.). Our study suggests sharks are capable of being classically conditioned to recreational fishing activities and depredation rates are influenced by fisher behaviour. We have highlighted possible mitigation strategies designed to un-condition sharks to recreational fishing, including modifying fishing practices, use of deterrents based on the sensitivity of shark senses and management strategies. The best approach is likely to be enabling fishers to become more knowledgeable of how and why shark depredation events happen and take appropriate steps to avoid them.

scholarly journals Drivers of variation in occurrence, abundance, and behaviour of sharks on coral reefs

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
E. Lester ◽  
T. Langlois ◽  
I. Lindgren ◽  
M. Birt ◽  
T. Bond ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Spatial Scales ◽  
Conservation Strategies ◽  
Time Of Arrival ◽  
Carcharhinus Plumbeus ◽  
North West ◽  
The Status ◽  
Video Systems ◽  
Reef Sharks ◽  
Species Specific

AbstractQuantifying the drivers of population size in reef sharks is critical for the development of appropriate conservation strategies. In north-west Australia, shark populations inhabit coral reefs that border growing centres of human population, industry, and tourism. However, we lack baseline data on reef sharks at large spatial scales (hundreds of km) that might enable managers to assess the status of shark populations in the face of future development in this region. Here, we examined the occurrence, abundance and behaviour of apex (Galeocerdo cuvier, Carcharhinus plumbeus) and reef (C. amblyrhynchos, C. melanopterus, Triaenodon obesus) sharks using > 1200 deployments of baited remote underwater stereo-video systems (stereo-BRUVs) across > 500 km of coastline. We found evidence for species-specific influences of habitat and fishing activities on the occurrence (probability of observation), abundance (MaxN) and behaviour of sharks (time of arrival to the stereo-BRUVs and likelihood of feeding). Although the presence of management zoning (No-take areas) made little difference to most species, C. amblyrhynchos were more common further from boat ramps (a proxy of recreational fishing pressure). Time of arrival for all species was also influenced by distance to boat ramp, although patterns varied among species. Our results demonstrate the capacity for behavioural metrics to complement existing measures of occurrence and abundance in assessing the potential impact of human activities on shark populations.

Concepts and Practices for Improving Nitrogen Management for Vegetables

1992 ◽  
Vol 2 (1) ◽  
pp. 121-125 ◽  
Author(s):  
George J. Hochmuth
Keyword(s):  
Water Management ◽  
Management Practices ◽  
Management Strategies ◽  
N Fertilization ◽  
Nitrogen Management ◽  
Land Grant ◽  
Land Grant Universities ◽  
Production Practices ◽  
Negative Impacts ◽  
N Management

Efficient N management practices usually involve many potential strategies, but always involve choosing the correct amount of N and the coupling of N management to efficient water management. Nitrogen management strategies are integral parts of improved production practices recommended by land-grant universities such as the Institute of Food and Agricultural Sciences, Univ. of Florida. This paper, which draws heavily on research and experience in Florida, outlines the concepts and technologies for managing vegetable N fertilization to minimize negative impacts on the environment.

scholarly journals Identification of Risks Pertaining to Abandoned Housing Projects in Malaysia

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Hamzah Abdul-Rahman ◽  
Chen Wang ◽  
Nur Hamizah Ariffin
Keyword(s):  
Construction Projects ◽  
Quantitative Methods ◽  
Management Strategies ◽  
Mitigation Strategies ◽  
Housing Projects ◽  
Qualitative And Quantitative Methods ◽  
Risk Management Strategies ◽  
Housing Industry ◽  
Ground Condition ◽  
Very High

Housing industry is one of the most dynamic, risky, and challenging industries. In Malaysia, this industry has a poor reputation for managing risks, with many major projects failing to be completed within the allotted time. Due to the inherent risks involved in construction projects, it is essential to recognize the risks that cause problems associated with abandoned housing projects. Therefore, this study aims to identify the risks that contribute to issues of abandoned housing projects and to propose mitigation strategies. The methodologies used in this study are combination of qualitative and quantitative methods of literature review, questionnaire survey, and interview. The results show that many risks are involved in housing project, including risks related to environmental impacts, construction, politics, law, management, finance, materials, and economy, of which the probability of risks from unexpected ground condition, project delays, bureaucracy, contractual disputes between developer and landlord, weakness in management by inexperience developer, and financial crisis is very high. It was also found that all relevant parties involved in housing industry are required to have extensive cooperation in advance and should perform systematic risk management strategies in order to mitigate the risks leading to problems associated with abandoned housing projects.

The Angler in the Environment: Social, Economic, Biological, and Ethical Dimensions

2011 ◽  
Keyword(s):  
Best Practices ◽  
Best Practice ◽  
Research Question ◽  
Management Strategies ◽  
Leisure Activity ◽  
Quality Data ◽  
Fish Stocks ◽  
Catch And Release ◽  
Practice Behaviors ◽  
Negative Impacts

<i>Abstract</i> .—Recreational fishing is popular worldwide. However, the potential negative impacts of this leisure activity can influence the sustainability of targeted fish stocks. Although management strategies are frequently used to control the actions of anglers, participants themselves must ultimately be confident that changes in their behavior will lead to the conservation of recreational fish stocks before regulations are followed and best practices adopted. Directly involving recreational anglers in research used to quantify the value of best practices, such as in the case of catch and release, can help reinforce the notion among anglers that best practice behaviors facilitate conservation and sustainable exploitation. Using the framework of citizen science and the principles of experiential education (immersion, involvement, ownership, and legacy), we present a case study whereby recreational anglers were directly involved in research that tested how attributes of catch-and-release fishing for bonefish <i>Albula </i> spp. can influence the postrelease survival. By accompanying anglers to the shallow flats and actively involving them in hands-on research aimed at addressing relevant behaviors in the context of catch and release, such programs can promote an increased awareness and sense of personal ownership over the research question and the conservation benefits that it intends to facilitate. With data generated through direct involvement, the participation of recreational anglers in our research culminated in the development of a best practices brochure about catch and release for bonefish. It is our experience that research programs involving recreational anglers need to be well conceived and structured so as to adequately balance the quality of the experience for the participants with the need for generating quality data. Welldesigned “research angler” programs as a form of tourism or even ecotourism could help scientists not only to enhance their ability to conduct fisheries research, but also to broaden the impacts of their research program and the speed at which best practices are adopted.

Risk Management Strategies for Project Success

2018 ◽  
pp. 250-267
Author(s):  
Vittal S. Anantatmula ◽  
Yang Fan
Keyword(s):  
Risk Management ◽  
Project Success ◽  
Risk Mitigation ◽  
Management Strategies ◽  
Management Plan ◽  
Mitigation Strategies ◽  
Risk Management Plan ◽  
Industrial Sectors ◽  
Risk Management Strategies ◽  
Risk Mitigation Strategies

As projects are associated with risks due to the presence of uncertainties and unknowns, risk management assumes importance in project success. This chapter is an attempt to examine various risk mitigation strategies that are commonly employed if different industrial sectors. The chosen risk strategy would also largely depend either on individual's or organization's propensity to take risks. The authors summarize the findings of a research study in this chapter. The research results show that effort and details of a risk management for a project are governed by risks associated with cost and time and not necessarily with the project scope. Also, many organizations prefer a contingency budget to the project plan to developing a detailed risk management plan.

scholarly journals Invasive alien palm Pinanga coronata threatens native tree ferns in an oceanic island rainforest

2018 ◽  
Vol 66 (8) ◽  
pp. 647 ◽  
Author(s):  
Michael J. B. Dyer ◽  
Gunnar Keppel ◽  
Marika Tuiwawa ◽  
Sainivalati Vido ◽  
Hans Juergen Boehmer
Keyword(s):  
Linear Models ◽  
Management Strategies ◽  
Ornamental Plants ◽  
Native Plant ◽  
Ecological Processes ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Tree Ferns ◽  
Native Tree ◽  
Negative Impacts

Invasive ornamental plants are a global problem that can have severe impacts on native biodiversity, especially on islands. To determine whether the invasive, ornamental ivory-cane palm Pinanga coronata could be displacing native biodiversity, we investigated its co-distribution with native tree ferns in a Fijian rainforest. We recorded the abundances of P. coronata and tree ferns and related these to environmental variables using linear models and generalised linear mixed-effect models (GLMMs). Distance to an introduction site was the most significant factor predicting the palm’s distribution and abundance, suggesting that its current distribution is limited by insufficient time for wider dispersal. P. coronata cover was strongly and negatively related with the abundance of native tree ferns and the palm may therefore be displacing native tree ferns. This relationship was strongest with tree fern seedlings and weakest with mature tree ferns, implying that the palm is preventing the establishment of native tree ferns. This study thus provides strong circumstantial evidence that P. coronata is progressively displacing native tree ferns by preventing seedling establishment and poses a severe threat to Fiji’s native biodiversity and ecological processes. Therefore, urgent management is required to control and prevent the further spread of P. coronata and its negative impacts on native plant biodiversity. Management should involve an initial feasibility study to determine the effectiveness of various management strategies, followed by targeted control and/or eradication campaigns and long-term monitoring. Ultimately, well implemented legislation to prevent the spread and introduction of P. coronata and other ornamental plants will be crucial to protect native biodiversity in Fiji and elsewhere.

Tracing fine sediment sources in small mountain catchment

2011 ◽  
Vol 63 (10) ◽  
pp. 2324-2330 ◽  
Author(s):  
A. Kouhpeima ◽  
S. Feiznia ◽  
H. Ahmadi
Keyword(s):  
Magnetic Susceptibility ◽  
Organic Contaminants ◽  
Function Analysis ◽  
Management Strategies ◽  
Fine Sediment ◽  
Mitigation Strategies ◽  
Catchment Management ◽  
Sediment Sources ◽  
Diffuse Source ◽  
And Control

Fine sediment represents an important diffuse source pollutant in surface waters, due to its role in governing the transfer and fate of many substances, including nutrients, heavy metals, pesticides and other organic contaminants, and its influence on aquatic ecology. Therefore, catchment management strategies frequently need to include provision for the control of sediment mobilization and delivery. The sediment tracing concept provides a valuable framework for assisting the management and control of diffuse source sediment pollution by identifying the key sources and demonstrating the importance of intermediate storages and the likely impact of upstream mitigation strategies on downstream sediment and sediment associated contaminant fluxes. In this research, fine sediment sources were identified using tracing method. By field works, sediments were sampled from dam reservoir, different sources were also sampled. Fifteen tracers were first selected for tracing which are: The amounts of N, P, C, Cr, Co, Mg, K, Na, smectite, chlorite, illite, kaolinite, and two magnetic properties consisting of Low Frequency Magnetic Susceptibility (XLF) and Frequency Dependent Magnetic Susceptibility (XFD). The samples were analyzed in the laboratory for these parameters and different statistical methods were applied to the data including Non-parametric Kruskal–Wallis Test and Stepwise Discriminant function analysis. The results provide important information on the relative importance of fine sediment sources to the reservoir sediments, which can be used to support model validation and the targeting of management and control strategies.

Shore-based recreational angling in the Rottnest Island Reserve, Western Australia: Spatial and temporal distribution of catch and fishing effort

2006 ◽  
Vol 12 (3) ◽  
pp. 238 ◽  
Author(s):  
C. B. Smallwood ◽  
L. E. Beckley ◽  
N. R. Sumner
Keyword(s):  
Western Australia ◽  
Temporal Distribution ◽  
Fishing Effort ◽  
Recreational Fishing ◽  
Temporal Data ◽  
Target Species ◽  
Southwestern Australia ◽  
Recreational Angling ◽  
Western Australian ◽  
Support Decision Making

The Rottnest Island Reserve, located off southwestern Australia, is one of the most popular recreational fishing locations in Western Australia. In the reserve, standard Western Australian recreational fishing regulations apply and there are two small "no-take" conservation sanctuary areas. A roving creel survey of shore-based recreational angling in the reserve was conducted from January to December 2003. In total, 1 053 anglers were recorded which included individuals, families, school groups and angling club members. The total annual shore-based angling effort for Rottnest island was calculated to be 23 899 angler outings and the total catch estimated at 53 994 retained fish. Fishing effort was concentrated in the settlement area on the eastern side of the island and the highest levels of catch and effort were recorded in April, May and July. During the survey, 33 fish species were identified in the catch and the small, pelagic species Australian Herring dominated with 7.27 tonnes caught during the study. Shore-based anglers also caught and released a large number of non-target species. The survey has provided spatial and temporal data that can be used as a benchmark and to support decision making by the Rottnest Island Authority with respect to biodiversity conservation and the Department of Fisheries with regard to management of shore-based recreational angling in the Rottnest Island Reserve.

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