11th ICRS Abstract book - Nova Southeastern University
11th ICRS Abstract book - Nova Southeastern University
11th ICRS Abstract book - Nova Southeastern University
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22-21<br />
Applying An Optimal Resource Space Concept To Small Scale Reef Fisheries<br />
Management<br />
Lydia TEH* 1 , Louise TEH 1<br />
1 Fisheries Centre, <strong>University</strong> of British Columbia, Vancouver, BC, Canada<br />
Fishers operate according to an optimal resource space whose boundaries are defined by<br />
economic profitability, technological sophistication, and socio-cultural preferences.<br />
These 'invisible' boundaries can affect fishers’ willingness to comply with, and ability to<br />
adapt to spatial restrictions. Better understanding of the factors that shape optimal<br />
resource spaces can thus lead to management decisions that are more aligned with<br />
fishers’ perspectives and have a higher likelihood of being complied with and adopted.<br />
We investigate the coral reef fisheries of Pulau Banggi, Sabah, Malaysia, where a marine<br />
protected area is proposed. Our objectives are i) map fishers’ optimal resource space; ii)<br />
explain ecological, socio-cultural, and economic factors that influence fishers’ optimal<br />
resource space; and iii) apply optimal resource space concept to spatial management of<br />
small scale reef fisheries. We use data from fish catch log<strong>book</strong>s to track the fishing<br />
activities of 21 fishers. We conducted semi-structured interviews with fishers to explore<br />
factors that dictate their resource use space, including market forces, fishers’ motivations<br />
and perceived constraints. We find that fishers function within an optimal resource space<br />
that is delineated by socio-cultural factors such as family ties, and distance from resident<br />
village. Even though fishers are aware of locations where they perceive more fish can be<br />
caught, they rarely fish those places. While Banggi fishers face invisible boundaries that<br />
restrict them to habituated fishing grounds, outsider fishers do not face such restrictions<br />
and are not prevented from exploiting Banggi’s open access fisheries. The optimal<br />
resource space concept can be applied towards analyzing user conflict, compliance, and<br />
equity issues. In the context of marine protected areas, it can help in designing spatial<br />
management strategies that are socially acceptable and ecologically sustainable to<br />
fisheries and fishing communities.<br />
22-22<br />
Improving Management Of Coral Reef Fisheries in Data Limited Situations:<br />
Experiences From The Parfish Methodology<br />
Robert WAKEFORD* 1 , Suzannah WALMSLEY 2 , Robert TRUMBLE 1 , Paul<br />
MEDLEY 3<br />
1 MRAG Americas, Inc., Saint Petersburg, FL, 2 MRAG Ltd., London, United Kingdom,<br />
3 Independent Consultant, Alne, United Kingdom<br />
Coral reef fisheries are complex systems. This is due primarily to the multi-species,<br />
multi-gear and high labour mobility that often occurs within the fisheries sector. Since<br />
many small-scale fisheries operate in remote areas and/ or in developing coastal states,<br />
the quality and quantity of data necessary to undertake basic fisheries management,<br />
including robust stock assessments, are often lacking. However, it is becoming more<br />
widely acknowledged that local stakeholder participation is an essential pre-requisite to<br />
improve overall management of the resource, but this has rarely engaged them directly<br />
within a stock assessment framework to provide information on the status of the resource.<br />
This study presents a summary and comparison of three pilot studies undertaken in Turks<br />
and Caicos, Tanzania and Puerto Rico that have been used to demonstrate a new fisheries<br />
management tool that enables stakeholders to participate directly in the stock assessment<br />
process. Through the development of a participatory fish stock assessment (ParFish)<br />
methodology, fishers are engaged at the beginning of the management process to<br />
contribute their valuable knowledge about the fishery. Using a Bayesian statistical model,<br />
information obtained from fishers help inform prior statistical distributions that are used<br />
to estimate parameters in the stock assessment model. The results have shown that this<br />
approach can be used successfully to establish preliminary estimates of stock status in<br />
data limited situations.<br />
Oral Mini-Symposium 22: Coral Reef Associated Fisheries<br />
22-23<br />
Effectiveness Of Minimum Legal Size As A Fisheries Management Tool in A Multi-<br />
Sectoral Reef Fishery<br />
Sara BUSILACCHI* 1,2 , Gavin BEGG 3 , Ashley WILLIAMS 2<br />
1 School of Marine and Tropical Biology, James Cook <strong>University</strong>, Townsville, Australia,<br />
2 Fishing and Fisheries Centre, School of Earth and Environmental Science, James Cook<br />
<strong>University</strong>, Townsville, Australia, 3 Australian Fisheries Management Authority, Canberra,<br />
Australia<br />
Minimum legal size (MLS) is one of the oldest and most widely accepted management tools in<br />
fisheries and is usually based on the mean length at which 50% of a population become mature.<br />
The effectiveness of a MLS depends on a range of factors including the biology of the species,<br />
fishing behaviour, fishing gear, post-release survival, other management arrangements and<br />
compliance. In this presentation we assess the effectiveness of MLS’s when applied to manage<br />
two of three sectors in a multi-sectoral fishery. The reef finfish fishery in Torres Strait,<br />
Australia, is shared among three sectors: an indigenous subsistence sector and two commercial<br />
sectors (an indigenous and a non-indigenous). In an effort to retain its cultural value, the<br />
subsistence sector is currently not regulated. However, the two commercial sectors are managed<br />
by numerous regulations including a MLS for the commercially important species. It is normal<br />
practice within indigenous communities for subsistence fishing to occur during commercial<br />
fishing trips, even though this is inconsistent with legislation. Subsistence catch taken during<br />
commercial fishing trips was monitored between May 2005 and May 2006 using an access<br />
point survey in three Torres Strait communities. We estimated that, on average, 22% of the total<br />
catch taken during commercial trips is used for subsistence. Coral trouts (Plectropomus spp.),<br />
carangids and snappers (Lutjanus spp.) were the most retained species for subsistence and were<br />
also the most commercially important. Results showed that, for some of these species, undersize<br />
fish (less than the MLS) represented 80% of the subsistence catch taken during commercial<br />
fishing trips. We conclude that the effectiveness of this management tool relies on the<br />
understanding of its rationale and its acceptance by indigenous communities.<br />
22-24<br />
Bias Of Cpue Revealed By Considering Fisheries As Predator Prey Systems<br />
Meaghan C. DARCY* 1 , Steven JD MARTELL 2<br />
1 Zoology / Fisheries Center, <strong>University</strong> of British Columbia, Vancouver, BC, Canada,<br />
2 Fisheries Center, <strong>University</strong> of British Columbia, Vancouver, BC, Canada<br />
The Hawaiian bottomfish fishery is a multi-species fishery, where the target species (mainly<br />
eteline snappers and one grouper species) are associated with deep reef structures and are<br />
caught using handlines. This fishery exemplifies many reef associated, multi-species fisheries,<br />
where the fishing gear simultaneously captures multiple species. Assessment of status for each<br />
species is based on effort-aggregated commercial catch statistics and single-species assessment<br />
models. Aggregation of these data assumes that the capture probabilities and targeting of each<br />
species are constant over time and those species-specific catches per unit effort (CPUE) indices<br />
are proportional to abundance. Using single-species assessment models with effort-aggregated<br />
data may be problematic because the assumption of proportionality is likely to be violated due<br />
to changes in targeting and or changes in species composition and changes in fishing<br />
technologies.<br />
To account for species composition effects in the multi-species fisheries, we develop an effort<br />
dynamics sub-model that partitions the total effort into components of handling time and time<br />
spent searching (i.e., Holling’s Disc equation). It explicitly allows for handling time influences<br />
and the differences in catchability among target and non-target species. We tested this approach<br />
using stochastic simulation-estimation experiments, where the dynamics of individual fish<br />
populations that make up a multi-species fishery and typical fisheries dependent data (i.e.,<br />
species specific catch data and aggregate effort data). Simulation results demonstrate that<br />
increased handling time leads to a hyperstable index of abundance (i.e., catchability declines<br />
less rapidly than biomass) which would lead to overestimates of abundance in the classic singlespecies<br />
assessments. Ignoring handling time effects for fisheries such as, handline fisheries,<br />
where a large component of effort includes gear set-up and retrieval and removal of catch from<br />
the gear, results in biased abundance estimates.<br />
188