Unreported bycatch in the New Zealand West Coast South Island hoki fishery

Bremner, Graeme; Johnstone, P. D.; Bateson, Tracy; Clarke, P.

doi:10.1016/j.marpol.2008.11.006

Cited by 21 publications

(16 citation statements)

References 23 publications

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“…Discarding is prohibited in New Zealand for almost all species managed under the quota management system (QMS) and therefore cannot be considered as an alternative to landing catch in excess of ACE holding as, e.g., in The Netherlands. However, as in many fisheries worldwide, misreporting is believed to occur in the hoki fishery (Bremner et al 2009). In principle, New Zealand's fishers and/or quota-holders have two options: if landings are below ACE holding, quota-holders are allowed to carry forward up to 10% of their unused ACE into the next fishing year.…”

Section: Introductionmentioning

confidence: 99%

Catch-quota balancing in mixed-fisheries: a bio-economic modelling approach applied to the New Zealand hoki (Macruronus novaezelandiae) fishery

Marchal

Francis

Lallemand³

et al. 2009

Aquat. Living Resour.

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-Managing adequately the exploitation of commercial species subject to technical interactions is a key step towards the ecosystem approach to fisheries. We evaluate here, using a bio-economic modelling approach building on the ISIS-Fish simulation platform, the relative impact of total allowable commercial catches (TACC) and of taxes applicable to over-quota landings (deemed value) on the sustainability of a selection of species exploited by the New Zealand hoki (Macruronus novaezelandiae) fishery. We investigate some aspects of the hoki mixed fisheries, consisting of four fleets and nineteen métiers, by considering the technical interactions between hoki and Southern hake (Merluccius australis). The dynamics of effort allocation were modelled using gravity model, using value per unit of effort (VPUE) as attractivity coefficient. Several management scenarios, based on different levels of TACC, effort limits and deemed value have been defined. The impact of these strategies on spawning biomass and catches has been investigated. The results confirm that the deemed value may, in combination with TACC, be an efficient management tool. By increasing the hoki deemed value, we could somehow limit the decrease in the hoki TACC needed to harvest Western hoki sustainably. Constraining hoki fishing also restricts Southern hake fishing in the Chatham Rise and in the West Coast South Island, but leads to increased targeting of this species in the Sub-Antarctic area. The relative costs of renting/buying quota or paying the deemed value are most constraining when the hoki TACC is at relatively low level and when the hoki deemed value is more than 1.5 times the current value.Key words: Fleet dynamics / New Zealand hoki fishery / Deemed value / Fisheries management Résumé -La gestion adéquate de l'exploitation d'espèces commerciales sujettes à des interactions techniques constitue un premier pas dans la direction de l'approche écosystémique des pêches. Nous évaluons ici, au moyen d'une approche de modélisation bio-économique s'appuyant sur la plate-forme de simulation ISIS-Fish, l'impact relatif du total admissible de captures commerciales (TACC) et de taxes appliquées aux débarquements « hors quota » (taxes sur leur valeur estimée), sur la conservation d'une sélection d'espèces exploitées par la pêcherie de hoki (Macruronus novaezelandiae) néo-zélandaise. Nous étudions certains aspects de la pêcherie mixte de hoki, représentée par quatre flottilles et dix-neuf métiers, en considérant les interactions techniques entre le hoki et le merlu austral (Merluccius australis). La dynamique de l'allocation de l'effort de pêche a été modélisée en utilisant un modèle de gravité, dans lequel la valeur par unité d'effort (VPUE) représente le coefficient d'attractivité. On a défini plusieurs scénarios de gestion, basés sur différents niveaux de TACC, de limitation d'effort de pêche et de la taxe. L'impact de ces stratégies sur la biomasse féconde et les captures a été étudié. Les résultats confirment que la taxe, combinée avec les TA...

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Section: Introductionmentioning

confidence: 99%

Catch-quota balancing in mixed-fisheries: a bio-economic modelling approach applied to the New Zealand hoki (Macruronus novaezelandiae) fishery

Marchal

Francis

Lallemand³

et al. 2009

Aquat. Living Resour.

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“…For example, comparisons between observer data and logbook data have been used to investigate the nature of discrepancies in total catch, areas fished, and trip duration within the fisheries of the northeast United States (Rago et al, 2005), New Zealand (Bremner et al, 2009), and the North Sea (Borges et al, 2008). These studies did not, however, Fig.…”

Section: Discussionmentioning

confidence: 99%

A field test of fisheries observer sampling methods for estimation of at-sea discards

Cahalan

Faunce

Bonney³

et al. 2016

Fisheries Research

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a b s t r a c tEstimation of at-sea discards is an issue that has received considerable attention worldwide. With this increasing focus, there is a need for greater precision of weight estimates for less common and fisherylimiting species. While one solution is to mandate full (100%) observer coverage to reduce uncertainty in estimation at the trip level, variance from on-deck sampling methods (e.g. within-haul) should also be properly addressed. Commercial fishing vessels are not perfect sampling platforms and all sampling methods suffer from implementation issues that potentially impact the quality of the data collected and the resulting estimates. We conducted a cooperative study with industry to evaluate two observer sampling methods on trawl vessels delivering their catch to shoreside processors. The alternative observer sampling method that targets the portion of the haul that would be discarded directly at-sea, relying on shoreside reports of retained catch to generate total catch estimates, was tested against the standard methods currently used by the NMFS North Pacific Groundfish and Halibut Observer Program that sample the entire catch, both retained and discarded portions (combined). Methods were tested simultaneously by deploying two observers to sample each haul on study trips within three Gulf of Alaska trawl fisheries that varied widely in amount and species composition of discards: Rockfish Program, arrowtooth flounder, and shallow water flatfish. Although the alternative method was successfully implemented in two of the three fisheries, logistical constraints decreased sampling effectiveness in the third. In some situations, observers were unable to collect multiple samples under both methods, preventing variance estimation. This occurred more often for the observer using standard methods. Detection of less common and rare species was higher using the alternative sampling method. Discard estimates from the two methods were found to be significantly different in two of the fisheries examined (Rockfish Program and arrowtooth flounder). Discard estimates under the alternative method tended to have smaller variances than for the standard method, although this was not universally the case. These results provide an important comparison of the relative performance of different on-deck sampling methods under varying catch conditions and fisheries.

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“…The fisher facing Deemed Value on the catch in excess of ACE may consider discarding bycatch. Bremner et al [2] provide evidence from the Hoki fishery (a mixed species fishery on the West Coast of New Zealand) that fishers discard bycatch when ACE is not available. This is clearly undesirable and in breach of fisheries regulations and if detected can result in substantial penalties for the fisher.…”

Section: Introductionmentioning

confidence: 99%

“…2 In New Zealand society iwi is the Maori word for a tribe and represents the largest social unit in Maori culture. 3 Paua is the Māori name given to large edible sea snails (marine gastropod molluscs), known elsewhere as abalone.…”

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confidence: 99%