Length-Based Assessment of an Artisanal Albulid Fishery in the South Pacific: a Data-Limited Approach for Management and Conservation

Data-limited fisheries assessment methods have great potential to help inform small island communi

Substantial impacts of subsistence fishing on the population status of an Endangered reef predator at a remote coral atoll

Napoleon wrasse Cheilinus undulatus has declined drastically throughout most of its range, owing, in large part, to overexploitation. In Anaa, French Polynesia, the species is harvested as part of the subsistence catch by fishers using rockpile traps, spearguns, handmade harpoons, and baited handlines. We sampled 70 Napoleon wrasse captured by artisanal fishers of Anaa between 2015 and 2018 to assess the status of this population, and we applied data-poor fisheries models to assess the stock status of this iconic reef predator. The species was determined to be overexploited at a rate of 0.82 based on values of natural (0.14; Hoenig method) and fishing (0.58; difference of total and natural mortality) mortality as components of total mortality (0.72; Beverton-Holt estimation). The left-skewed length distribution (mean = 36 ± 13 cm SL) suggested an under-representation of large adults in the population, which would predominantly be terminal males in this sequentially hermaphroditic protogynous fish. This was not considered to be reflective of poor sel

The Movements of Predatory Reef Fishes in the Molokini Marine Life Conservation District

M.S. University of Hawaii at Manoa 2016.Includes bibliographical references.Predators play a critical role in maintaining the balance of marine ecosystems and are an important component of Hawaii’s recreational and commercial fisheries. In light of the increasing pressures on these populations in recent decades across the main Hawaiian Islands from both consumptive and non-consumptive resources use, the study of apex predator movements in marine protected areas has become a research priority. To this aim, we used passive acoustic telemetry to investigate the spatial and temporal movement patterns of five apex predators: bluefin trevally (Caranx melampygus), giant trevally (Caranx ignobilis), green jobfish (Aprion virscens), whitetip reef sharks (Triaenodon obesus) and grey reef sharks (Carcharhinus amblyrhynchos) at the 31 ha Molokini Marine Life Conservation District (MLCD) off Maui, Hawaii. The Molokini MLCD is the second most visited MLCD in the State of Hawaii with over 300,000 visitors per year. Our results indicate that residency was variable across species, with bluefin trevally exhibiting the highest residency in the MLCD and green jobfish the lowest. Bluefin trevally showed displacement from critical habitats in the MLCD during peak visitation hours. Long distance movements between the Molokini MLCD and the other islands of the Maui Nui Complex were common for grey reef sharks, giant trevally, and green jobfish. These results indicate that despite its small size, the Molokini MLCD provides a high level of protection to resident species such as bluefin trevally. However, this MLCD is less effective at protecting more mobile apex predators such as green jobfish, grey reef sharks, and giant trevally

Data from: Effects of gear restriction on the abundance of juvenile fishes along sandy beaches in Hawai'i

In 2007, due to growing concerns of declines in nearshore fisheries in Hawai‘i, a ban on gillnets was implemented in designated areas around the island of O‘ahu in the main Hawaiian Islands. Utilizing a 17 year time-series of juvenile fish abundance beginning prior to the implementation of the gillnet ban, we examined the effects of the ban on the abundance of juveniles of soft-bottom associated fish species. Using a Before-After-Control-Impact (BACI) sampling design, we compared the abundance of targeted fishery species in a bay where gillnet fishing was banned (Kailua, O‘ahu), and an adjacent bay where fishing is still permitted (Waimānalo, O‘ahu). Our results show that when multiple juvenile fish species were combined, abundance declined over time in both locations, but the pattern varied for each of the four species groups examined. Bonefishes were the only species group with a significant BACI effect, with higher abundance in Kailua in the period after the gillnet ban. This study addressed a need for scientific assessment of a fisheries regulation that is rarely possible due to lack of quality data before enactment of such restrictions. Thus, we developed a baseline status of juveniles of an important fishery species, and found effects of a fishery management regulation in Hawai‘i

The spawning migrations of an exploited Albulid in the tropical Pacific: implications for conservation and community-based management

International audienceTeleost fish that form predictable spawning aggregations and undertake reproductive migrations can be particularly vulnerable to overexploitation. To support community-based management of an artisanal fishery that targets bonefish (Albula glossodonta) spawning aggregations, we used a combination of acoustic telemetry, biological sampling, and remote imagery to reveal the spatiotemporal spawning migrations of bonefish on Anaa Atoll in the Tuamotu Archipelago, French Polynesia. The spawning migrations of bonefish tracked with acoustic telemetry were restricted to the northern section of the atoll, with 99.6% of all detections at offshore spawning habitats occurring on fixed acoustic receivers adjacent to the atoll’s artisanal fish trap complex. Male bonefish undertook spawning migrations more frequently than females and these spawning migrations were common during the Austral winter and fall. The movements of bonefish spawning aggregations coincided with the lunar cycle, as a network analysis revealed an increase in network size and the diversity of habitat use within our acoustic array throughout the duration of the waning moon. Our results highlighted the need for the management of the artisanal trap fishery to prevent the overharvest of bonefish during their peak spawning periods. In response to the spatiotemporal management recommendations derived from this research, the local government established an Educational Managed Marine Area that includes the atoll’s bonefish spawning migratory corridor adjacent to Tukuhora village and a Rahui (i.e., seasonal closure) to improve the sustainability of the fishery

Population dynamics of roundjaw bonefish Albula glossodonta at a remote coralline Atoll inform community-based management in an artisanal fishery

Fisheries management requires knowledge on the population dynamics of exploited stocks. To that end, the present study used a mark–recapture approach to characterise the population demographics of roundjaw bonefish Albula glossodonta (Forsskål) and their interaction with a data-limite

Factors influencing postrelease predation for a catch-and-release tropical flats fishery with a high predator burden

Postrelease predation (PRP) of fishes released by anglers is a potentially significant contributo

Effects of Gear Restriction on the Abundance of Juvenile Fishes along Sandy Beaches in Hawai'i.

In 2007, due to growing concerns of declines in nearshore fisheries in Hawai'i, a ban on gillnets was implemented in designated areas around the island of O'ahu in the main Hawaiian Islands. Utilizing a 17 year time-series of juvenile fish abundance beginning prior to the implementation of the gillnet ban, we examined the effects of the ban on the abundance of juveniles of soft-bottom associated fish species. Using a Before-After-Control-Impact (BACI) sampling design, we compared the abundance of targeted fishery species in a bay where gillnet fishing was banned (Kailua, O'ahu), and an adjacent bay where fishing is still permitted (Waimānalo, O'ahu). Our results show that when multiple juvenile fish species were combined, abundance declined over time in both locations, but the pattern varied for each of the four species groups examined. Bonefishes were the only species group with a significant BACI effect, with higher abundance in Kailua in the period after the gillnet ban. This study addressed a need for scientific assessment of a fisheries regulation that is rarely possible due to lack of quality data before enactment of such restrictions. Thus, we developed a baseline status of juveniles of an important fishery species, and found effects of a fishery management regulation in Hawai'i

beach_seine_BACI

beach_seine_BACI.csv is a comma-separated file containing data from beach seine surveys of juvenile fish populations from two sites on windward side of Oahu, Hawai

Map of study area showing gillnet prohibited area (hatched area) in Kailua Bay and open area in Waimanalo Bay (A) on the island of O‘ahu in Hawai‘i (B).

<p>Red circles show sampling locations, and depth contours are colored from light (shallow) to dark (deep).</p