Papers by Jeremy McKenzie
Can otolith chemistry predict the natal origins of grey mullet(Mugil cephalus)?
Integrating multi-disciplinary data sources relating to inshore fisheries management via a Bayesian network
Ocean & Coastal Management, 2021
The move towards broader management of marine ecosystems has received significant momentum in rec... more The move towards broader management of marine ecosystems has received significant momentum in recent years. Fundamental to Ecosystem-Based Management (EBM) and Ecosystem-Based Fisheries management (EBFM) is the need to engage relevant stakeholder groups. Here we present a Bayesian network (BN) tool developed to describe the snapper population in the Hauraki Gulf, New Zealand, and investigate possible outcomes of alternative management scenarios on snapper abundance. The Hauraki Gulf is a location where the marine environment is both highly valued and in high demand for the goods and services it provides. Snapper are a key component of this social–ecological system. We developed a BN focussed on key snapper life stages, and the consequences of stressors, including fishing, uses of marine space, land use practises (which influence sediment and nutrient yield), biogenic and environmental habitat variables, and upper level drivers such as climate change, human population growth and the ...
An Integrated Multistock Multiarea Assessment Model for New Zealand Snapper ( Chrysophrys auratus ) Incorporating Home Fidelity Movement
An uncertain future: Effects of ocean acidification and elevated temperature on a New Zealand snapper (Chrysophrys auratus) population
Marine Environmental Research
Advances in Fish Tagging and Marking Technology
.—Fisheries managers in the Laurentian Great Lakes annually stock over 30 million salmonines (sal... more .—Fisheries managers in the Laurentian Great Lakes annually stock over 30 million salmonines (salmon and trout) to diversify sport fisheries, restore native fish populations, and control invasive fishes. However, little is known about how well these fish survive, contribute to the fisheries, and reproduce in the wild. As a result, the Council of Lake Committees (CLC), a basin-wide group of fishery managers that operates under the auspices of the Great Lakes Fishery Commission, agreed in 2005 to develop a basin-wide program to mark all stocked salmonines. This marking effort would provide greater insight into survival of stocked fish, the contribution of stocked adults to restoration of native fishes, the ability to manage harvest away from wild fish, and the opportunity to evaluate and improve hatchery operations. After evaluating the available marking and tagging options, the CLC chose to pursue mass-mark ing of all stocked salmonines. The program is based on the Pacific Northwest Pacific salmon Oncorhynchus sp. marking program and utilizes adipose fin-clips and coded-wire tags. When fully developed, the program aims to tag all hatchery-reared trout and salmon released in to the Great Lakes (about 30 million annually). The full program will require nine automated trailers and four manual trailers (total equipment costs: $13.7 million U.S. in 2007). Annual operations including tags, recovery efforts, and tag extraction services, will cost about $5.9 million. An operational plan has been completed to mark all fish prior to stocking, and to recover tagged fish as part of regular fishery surveys from anglers, commercial fishers, and charter boat operators. A data management system will be developed to cooperatively archive and analyze recovery data to answer questions of lake-wide or basin-wide scope. Efforts are underway to communicate to stakeholders the benefits of mass marking and to secure the necessary funding for equipment and annual operations. Project leaders expect this program to be fully implemented within five years but that schedule is predicated on funding levels and subsequent agency commitment. This project is an excellent example of cooperative, proactive efforts to improve and refine fisheries management across the Great Lakes basin.
Development of an age–length structured model of the Hauraki Gulf–Bay of Plenty snapper ( Pagrus auratus ) population
Marine and Freshwater Research, 2006
The development of a population model in which population state is defined by a matrix of numbers... more The development of a population model in which population state is defined by a matrix of numbers at age and length is described. Functional forms for processes that fitted Hauraki Gulf–Bay of Plenty (New Zealand) snapper (Pagrus auratus) population data were developed. The model was fitted to: commercial and research samples of proportions at age and length, commercial samples of proportions at age, tag–recapture estimates of numbers at length, a catch per unit effort abundance index, and sea surface temperature data. For each age–length element of the state matrix, the model determines a transition vector that gives a distribution of non-negative growth increments. Mean growth is both length- and age–length-dependent, but also varies between years. Annual mean growth and annual year-class strength were both found to be positively related to sea surface temperature, but during different seasons. It was also found that variations in growth between years resulted in moderate and sust...
Evidence from tag recapture experiments that fish learn to avoid fishing gear
Journal of Agricultural Biological and Environmental Statistics, Jun 1, 2001
Page 1. Evidence From Tag Recapture Experiments That Fish Learn to Avoid Fishing Gear David J. GI... more Page 1. Evidence From Tag Recapture Experiments That Fish Learn to Avoid Fishing Gear David J. GILBERT, Jeremy R. MCKENZIE, and Nicholas M. DAVIES We found evidence that tagging induced trap shyness in snapper ...
Canadian Journal of Fisheries and Aquatic Sciences, Apr 12, 2011
Intraspecific variation in movement patterns are well established for many species, but poorly ap... more Intraspecific variation in movement patterns are well established for many species, but poorly appreciated in fisheries management. In this study we dart-tagged snapper (Pagrus auratus), an important fishery species, across different areas and habitats in the Hauraki Gulf, New Zealand. Tag returns were used to quantify movement behaviour and extraction rates using a maximum likelihood model that corrected for spatial variability in population size and fishing effort. Residency was high (~90%) in two strata and lower (75%) in the remaining stratum. The stratum with the highest residency also appeared to experience the highest extraction rate (likely due to a lower population size). These results confirm the existence of differences in movement behaviour within the snapper population, suggesting that localized areas may become depleted regardless of the status of the overall stock. This has consequences for the scale of fisheries management and the size of marine reserves implemented in different regions. Understanding why variation in movement behaviour exists (i.e., genetic vs. environmental) is the next step in addressing the influence of animal behaviour on fisheries management.
A fisheries perspective of behavioural variability: differences in movement behaviour and extraction rate of an exploited sparid, snapper ( Pagrus auratus )
Canadian Journal of Fisheries and Aquatic Sciences, 2011
... We are also grateful to Cameron Walsh, Nicola Rush, Melanie Vaughan, Oliver Hannaford, Jarrod... more ... We are also grateful to Cameron Walsh, Nicola Rush, Melanie Vaughan, Oliver Hannaford, Jarrod Walker, Helena Armiger, Holly Ferguson, Catriona Paterson, and Keren Spong for assistance with tagging; Graeme Bailey and the crews of the fishing vessels Triton, Maggie J ...
Canadian Journal of Fisheries and Aquatic Science, 2017
Fishery management decisions are commonly guided by stock assessment models that aggregate output... more Fishery management decisions are commonly guided by stock assessment models that aggregate outputs across the spatial domain of the species. With refined understanding of spatial population structures, scientists have begun to address how spatiotemporal mismatches among the scale of ecological processes, data collection programs, and stock assessment methods (or assumptions) influence the reliability, and ultimately, appropriateness of regional fishery management (e.g., assigning regional quotas). Development and evaluation of spatial modeling techniques to improve fisheries assessment and management have increased rapidly in recent years. We overview the historical context of spatial models in fisheries science, highlight recent advances in spatial modeling, and discuss how spatial models have been incorporated into the management process. Despite limited examples where spatial assessment models are used as the basis for management advice, continued investment in fine-scale data collection and associated spatial analyses will improve integration of spatial dynamics and ecosystem-level interactions in stock assessment. In the near future, spatiotemporal fisheries management advice will increasingly rely on fine-scale outputs from spatial analyses.
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Papers by Jeremy McKenzie