Neil Loneragan

Catch per Unit Effort Dynamic of Yellowfin Tuna Related to Sea Surface Temperature and Chlorophyll in Southern Indonesia

Publisher: MDPI AG

Date: 31-08-2020

DOI: 10.3390/FISHES5030028

Abstract: Tuna fisheries are the most valuable fisheries in the world, with an estimated market value of at least US$42 billion in 2018. Indonesia plays an important role in the global tuna fisheries and has committed to improve its fisheries management therefore, a pilot of long-term spatial-temporal data bases was developed in 2012, however none have utilized data to have better understanding for management improvement. In this study, the annual and seasonal variation of large (≥10 kg) Yellowfin Tuna (YFT) catch per unit effort (CPUE) have been investigated and the influence of sea surface temperature (SST) and chlorophyll-a on these variables examined. We used fish landing data from West Nusa Tenggara recorded every month between 2012 and 2017 and analyzed using generalized linear models and generalized additive models. We found a seasonal and annual pattern of tuna abundance affected by SST and chlorophyll-a (chl a) and related to upwelling and El Nino event. These results also suggest that a two-month closure to fishing in August and September in southern Lombok is worth considering by the Government to maximize conservation of stocks due to a high abundance of juveniles emerging during the upwelling months from June to August.

Giant jelly eaters on the line: Species distribution and bycatch of three dominant sunfishes in the Southwest Pacific

Publisher: Elsevier BV

Date: 07-2018

DOI: 10.1016/J.ECSS.2018.03.017

Efficacy of restocking an estuarine-resident species demonstrated by long-term monitoring of cultured fish with alizarin complexone-stained otoliths. A case study

Publisher: Elsevier BV

Date: 07-2020

DOI: 10.1016/J.FISHRES.2020.105556

Different but not opposed: perceptions between fishing sectors on the status and management of a crab fishery

Publisher: Oxford University Press (OUP)

Date: 05-12-2019

DOI: 10.1093/ICESJMS/FSZ225

Abstract: Fisher perceptions are a useful source of information that allows changes in stocks to be detected quickly and indicate the social acceptability of different management regulations. Yet traditionally, such information is rarely employed when developing management approaches. Face-to-face interviews were used to elicit recreational and commercial fishers’ perceptions of a crab (Portunus armatus) fishery in three south-western Australian estuaries. Differences in the perceived changes in the average size of crabs and fishing effort, reported concerns and supported solutions were detected among the recreational fishers utilizing the three estuaries and between recreational and commercial fishers in the Peel-Harvey Estuary. However, some common views were expressed by recreational and commercial fishers, with both sectors stating concerns over recreational fisher compliance and increased fishing and environmental pressures. While both sectors believed that reducing fishing and increasing compliance would benefit crab stocks, the mechanisms for achieving this differed. Recreational fishers favoured increasing the length of the seasonal closure, while commercial fishers favoured the introduction of a recreational shore-based fishing licence. These findings suggest that sector- and estuary-specific management rules may better facilitate the amelioration of pressures affecting in idual estuaries and could contribute towards a more socially and biologically sustainable fishery.

Selecting from the Fisheries Managers’ Tool-Box: Recreational Fishers’ Views of Stock Enhancement and Other Management Options

Publisher: MDPI AG

Date: 14-09-2023

DOI: 10.3390/FISHES8090460

Differences in Recreational Fishers’ Motivations for Utilising Two Estuarine Fisheries

Publisher: MDPI AG

Date: 29-05-2023

DOI: 10.3390/FISHES8060292

Abstract: Effective fisheries management requires an understanding of human dimensions. This study elicited the salient motivations for recreational blue swimmer crab and black bream fishing in Western Australia and whether these views differed depending on the fishing location and/or the characteristics of the fisher. Crab fishers were strongly consumption-orientated and aimed to “catch big crabs” and “catch enough crabs to eat”. Furthermore, 91% consumed their catch, with only 2% practicing catch-and-release fishing. In contrast, 81% of black bream fishers did so for the sport/challenge, with the strongest motivation being to catch a bream considerably above legal size and with food only selected by 15% of respondents most fishers released caught fish. The marked differences between the fisheries for the two species, which co-occur in the same estuaries, are likely driven by the accessible nature of the crab fishery, ease of catching crabs, the low cost of fishing equipment, and their taste. Fishing for black bream, however, requires more expensive equipment, patience, and a greater skill level. Fishers considered crabbing to be as important as other fishing and outdoor activities, whereas bream fishers considered bream fishing considerably more important, reflecting the trophy nature of this fishery.

Application of the Method Evaluation and Risk Assessment Tool for a Small-Scale Grouper Fishery in Indonesia

Publisher: MDPI AG

Date: 05-10-2023

DOI: 10.3390/FISHES8100498

Niche partitioning among social clusters of a resident estuarine apex predator

Publisher: Springer Science and Business Media LLC

Date: 15-11-2021

DOI: 10.1007/S00265-021-03091-4

Temporal changes in the growth of a crustacean species, Portunus armatus, in a temperate marine embayment: evidence of density dependence

Publisher: Oxford University Press (OUP)

Date: 18-12-2019

DOI: 10.1093/ICESJMS/FSZ229

Abstract: Growth is a key attribute influencing population dynamics and fishery production, and understanding factors that affect the growth of in iduals in a population is essential in fisheries science and management. This study analyses 18 years of fishery-independent trawl data to determine the relationships among temperature, density, primary productivity and growth of the blue swimmer crab, Portunus armatus, in a temperate marine embayment. Growth was modelled using mixture distribution analyses and cohort-specific seasonal growth curves to estimate the size of crabs at the age of 0.5 and 1.5 years. Growth was highly seasonal, with size-at-age increasing during the austral summer periods and slowing/ceasing during the cooler winter months. The results from the mixture models were used to estimate the mean size of the 0.5- and 1.5-year-old crabs in each year. Linear models showed that the mean size of adult P. armatus at 1.5 years was negatively related to the density of juvenile (0.5 year) crabs in the previous year (i.e. the same cohort) and chlorophyll a concentrations in this year. Increased chlorophyll a levels may increase the survival of larval and megalopal P. armatus, leading to density-dependent effects such as increased competition among juveniles for food and spatial resources, and ultimately, reduced growth.

Observations of parturition in humpback whales (Megaptera novaeangliae) and occurrence of escorting and competitive behavior around birthing females

Publisher: Wiley

Date: 07-09-2022

DOI: 10.1111/MMS.12864

Abstract: Documented cases of cetacean births in the wild are rare. While there are currently no direct observations of a complete humpback whale birth, they are one of the few large whale species where observers have been present during a birthing event. We compiled eye‐witnessed accounts of all known humpback whale birthing events and found nine well‐documented cases globally (three published and six “new” unpublished). In two‐thirds of the accounts another “escort” whale was present and in close association with the birthing female, and of these, most cases involved multiple escorts ( n = 4). We describe details of birthing events, including mother, neonate and escort(s)’ behavior, neonate appearance, and discuss reasons for escort presence during parturition. We note that immediately postpartum: (1) blood and/or placenta were not always apparent during above water observations, (2) females often (but not always) supported calves at the surface, (3) constant travel and tail slapping were typical neonate behaviors, (4) two cases of temporary calf abandonment ( min), and (5) evidence of shark scavenging (of placenta) and possible predation attempts (of neonate). Lastly, we suggest curled tail flukes as an additional trait for identifying neonates and note that fetal folds are not always evident in newborn humpback whales.

Residency, movement patterns, behavior and demographics of reef manta rays in Komodo National Park

Publisher: PeerJ

Date: 16-05-2022

DOI: 10.7717/PEERJ.13302

Abstract: The reef manta ray ( Mobula alfredi ) is a globally threatened species and an iconic tourist attraction for visitors to Indonesia’s Komodo National Park (NP). In 2013, manta ray fishing was banned in Komodo NP and its surroundings, preceding the nationwide manta ray protection in 2014. Over a decade ago, a previous acoustic telemetry study demonstrated that reef manta rays had high fidelity to sites within the park, while more recent photo-identification data indicated that some in iduals move up to 450 km elsewhere. Characterization of manta ray demographics, behavior, and a focused assessment on site use of popular tourism locations within the park is vital to assist the Komodo NP Management Authority formulate appropriate manta ray conservation and management policies. This study uses a long-term library ( MantaMatcher.org ) of photo-identification data collected by researchers and citizen scientists to investigate manta ray demographics and habitat use within the park at four sites frequented by tour operators: Cauldron, Karang Makassar, Mawan, and Manta Alley. Residency and movements of manta rays were investigated with maximum likelihood analyses and Markov movement models. A total of 1,085 in idual manta rays were identified from photographs dating from 2013 to 2018. In general, in idual manta rays displayed a higher affinity to specific sites than others. The highest re-sighting probabilities came from the remote southern site, Manta Alley. Karang Makassar and Mawan are only ~5 km apart however, manta rays displayed distinct site affinities. Exchange of in iduals between Manta Alley and the two central sites (~35.5 km apart) occurred, particularly seasonally. More manta rays were recorded traveling from the south to the central area than vice versa . Female manta rays were more mobile than males. Similar demographic groups used Karang Makassar, Mawan, and Manta Alley for foraging, cleaning, cruising, or courtship activities. Conversely, a higher proportion of immature manta rays used the northern site, Cauldron, where foraging was commonly observed. Fishing gear-related injuries were noted on 56 in iduals (~5%), and predatory injuries were present on 32 in iduals (~3%). Tourism within the park increased from 2014 to 2017, with 34% more e boats per survey at Karang Makassar and Mawan. The Komodo NP contains several distinct critical habitats for manta rays that encompass all demographics and accommodate seasonal manta ray movements. While the present study has not examined population trends, it does provide foundational data for such work. Continued research into manta ray abundance, long-range movements, and identifying and protecting other critical aggregation areas within the region is integral to securing the species’ recovery. We provide management recommendations to limit undue pressure on manta rays and their critical habitats from tourism.

Salted mullet: Protracted occurrence of Mugil cephalus under extreme hypersaline conditions

Publisher: Elsevier BV

Date: 10-2021

DOI: 10.1016/J.ECSS.2021.107533

A two-phase approach to elicit and measure beliefs on management strategies: Fishers supportive and aware of trade-offs associated with stock enhancement

Publisher: Springer Science and Business Media LLC

Date: 14-06-2019

DOI: 10.1007/S13280-019-01212-Y

Estimating biological parameters for penaeid restocking in an Australian temperate estuary

Publisher: Elsevier BV

Date: 02-2017

DOI: 10.1016/J.FISHRES.2016.09.007

Trophic flows, kelp culture and fisheries in the marine ecosystem of an artificial reef zone in the Yellow Sea

Publisher: Elsevier BV

Date: 12-2016

DOI: 10.1016/J.ECSS.2016.08.021

Influence of physico-chemical and biotic factors on the distribution of a penaeid in a temperate estuary

Publisher: Elsevier BV

Date: 03-2019

DOI: 10.1016/J.ECSS.2018.12.003

Baseline survey of the fish and invertebrate fauna of Hill Inlet, the northernmost estuary in south-western Australia

Publisher: Cold Spring Harbor Laboratory

Date: 21-06-2020

DOI: 10.1101/2020.06.21.163402

Abstract: Microtidal estuaries in Mediterranean climates are particularly vulnerable to the effects of anthropogenic degradation. This study provides the first data on the fish and benthic macroinvertebrate fauna of Hill Inlet, the northernmost estuary in south-western Australia. S ling was conducted in June 2019 (Austral winter), when water levels were very high due to recent heavy rainfall and the bar at the mouth of the estuary was intact. Surface salinities were oligohaline and declined along the longitudinal axis, ranging from 12 to 3. A marked halocline was present at most sites, resulting in pronounced hypoxia. High water levels precluded the use of a seine net at some sites to s le the nearshore fish fauna, however, two species were recorded ( Pseudogobius olorum and Acanthopagrus butcheri ), both of which complete their life-cycle within the estuary. Deeper, offshore waters, s led using gill nets, yielded only four species ( Mugil cephalus, A. butcheri, Adrichetta forsteri and Pomatomus saltatrix ), due to the bar at the mouth of the estuary being closed prior to s ling thus limiting recruitment from marine species. Ten benthic macroinvertebrates species were collected, representing mainly polychaetes, molluscs and crustaceans. The low number of species was likely caused by the hypoxia present throughout most of the bottom waters. Although these data represent a benchmark against which future changes can be detected, it is recommended that additional s ling is conducted when water levels are lower and the bar has been open to provide a more holistic assessment of the fauna of Hill Inlet.

An evaluation of an iterative harvest strategy for data-poor fisheries using the length-based spawning potential ratio assessment methodology

Publisher: Elsevier BV

Date: 11-2015

DOI: 10.1016/J.FISHRES.2014.12.018

University Of Western Australia

Location: Australia

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CSIRO Marine And Atmospheric Research

Location: Australia

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Murdoch University

Location: Australia

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Murdoch Univeristy

Location: Australia

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University Of Waterloo

Location: Canada

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Murdoch University Murdoch Veterinary School

Location: Australia

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Linkage Projects - Grant ID: LP0775000

Start Date: 06-2007

End Date: 12-2010

Amount: $396,444.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE100100203

Start Date: 2010

End Date: 12-2010

Amount: $700,000.00

Funder: Australian Research Council