Blue cod is a bottom-dwelling species endemic to New Zealand. They are found at a depth of up to 150 m and adults tend to vary in average size around the country, with smaller fish in northern regions and larger fish in the colder southern regions.
Blue cod is taken predominantly in inshore domestic fisheries with very little deepwater catch. The major commercial blue cod fisheries in New Zealand are off Southland (BCO5) and the Chatham Islands (BCO4). It is the most important recreational finfish in Marlborough, Otago, Canterbury, Southland and the Chatham Islands.
The Southern Islands fishery is almost entirely a pot fishery. In the past, many blue cod fishers were primarily rock lobster fishers. Therefore, the amount of effort in the blue cod fishery tended to depend on the success of the rock lobster season, with weather conditions in Southland affecting the number of “fishable” days.
Blue cod is managed by Fisheries New Zealand using the Quota Management System (QMS).
The risk assessment covers roughly 87% of all blue cod caught in New Zealand.
For more information, download the full Risk Assessment Report.
The risk assessment framework is used to assess the relative environmental risks of Australian and New Zealand wild caught fisheries on fish stocks and the aquatic environment.
Assessments are undertaken for each species according to multiple ‘units of assessment’ (UoAs). The UoA is a combination of target species/stock and the gear type used by the fishery. Each UoA is assessed against three components for target species, bycatch and ecosystems, and management systems. Each component has a number of performance indicators, which have associated criteria, scoring issues and scoring guideposts. For each UoA, each performance indicator is assigned a risk score according to how well the fishery performs against the scoring guideposts. The summary of risk scores by UoA are presented in the table below.
An assessment of the future ‘outlook’ over the short to medium-term (0-3 years) is provided against each component. Outlook scores are provided for information only and do not influence current or future risk scoring.
All risk assessments are conducted by an independent third party. The process only takes a few days and includes opportunities for management groups and government to provide input and peer review.
The information presented on this page is extracted from the independent species Risk Assessment Report.
Risk Assessment Summary
Component 1 of the risk assessment looks at the health of the population of target species including the current fishing effort and estimates a risk of overfishing.
The total allowable commercial catch (TACC) in BCO 4 has remained static since the early 1990s, although catches have generally increased over the same period and have slightly exceeded the TACC in some recent years. The relative exploitation rate has now declined since 2010–11 and in 2013–14 was below the overfishing threshold (where the proxy measure is based on mean relative exploitation rate for the period 2002–03 to 2013–14). The Ministry for Primary Industries has since concluded that the current catch and TACC are unlikely (< 40%) to cause the stock to decline. Accordingly, the harvest strategy is expected to achieve the stock management objectives.
Within the BCO5 fishery, stock projections indicate that under the assumptions of commercial catch at the current TACC and recruitment at recent levels the BCO 5 biomass is unlikely to change much over the next 10 years. With catches at the current TACC, the probability of the stock being less than either the soft or hard limit over the next five years is negligible. Given historical TACC adjustments, the harvest strategy appears responsive to the state of the stock and all of the elements work together toward achieving the stock management objectives.
Bycatch and ecosystems
Component 2 of the risk assessment looks at the risks around bycatch species and other environmental impacts of the fishery.
According to landings data, the BCO 4 retained catch is 99% blue cod and 1% “other”. The BCO 5 retained catch is also almost entirely blue cod (97%) with 1% each for conger eel and octopus and 2% for “other”. Information on discards is limited, although the Ministry for Primary Industries reports that there are few significant bycatch problems.
There is limited direct quantitative information on endangered, threatened and protected (ETP) species interactions in the blue cod fisheries, although qualitative information is sufficient to estimate the fishery related mortality and to support measures to mitigate impacts where necessary. Interactions between the blue cod fisheries and protected seabirds are minimal, albeit not known with precision for some protected species groups (e.g. corals).
The main impacts of the fishery on the ecosystem elements can be inferred from the stock assessments, QMS catch trends, and observer data that cover the target species, related species, and most levels of the ecosystem. The lack of significant levels of retained and discarded by-catch, limited ETP interactions and potentially limited benthic impacts indicate a limited ecosystem impact.
Component 3 of the risk assessment looks at the risks around the management systems of a fishery.
The Fisheries Act 1996 and subsequent amendments provide a binding legislative and legal framework for delivering the objectives of Components 1 and 2. Sections 10, 11, and 12 of the Fisheries Act establish the requirements for the decision-making process, and Section 10 further requires the use of best available information for all decisions. This results in measures and strategies to achieve the fishery-specific objectives. The Fisheries Act requirement for best available information leads to scientific evaluation in advance of decisions. The Fisheries Act further requires consultation with such persons or organisations as the Minister considers are representative of those classes of persons having an interest in the stock or the effects of fishing on the aquatic environment in the area concerned including Maori, environmental, commercial, and recreational interests.
While objectives broadly consistent with Components 1 and 2 are specified in the Act and Fisheries 2030, and are therefore implicit in the fishery specific management system, it is not clear that explicit short and long-term objectives for blue cod fisheries are in place at this stage. A National Blue Cod Strategy is currently under development by the Ministry for Primary Industries and may result in fishery specific objectives.
Summary of main issues
Main issues highlighted by the assessment are:
- The relative exploitation rate was above the overfishing threshold for BCO4 for a number of years from 2008-09, but has since declined below the threshold in 2013-14.
- There is limited information on non-target species impacts in the blue cod fishery, albeit impacts are probably minimal.
- There are no fishery specific management objectives at present, although a National Blue Cod Strategy is currently under development by the Ministry for Primary Industries.
The outlook below provides a qualitative judgement about the likely future performance of the fishery against the relevant risk assessment criteria over the short to medium-term (0-3 years). Assessments are based on the available information for the species and take into account any known management changes.
- Target species (BCO 4) - Stable: Although variable, recent levels of fishing intensity have been at or around FMSY.
- Target species (BCO 5) - Stable: Stock projections indicate that at the current TACC and recruitment at recent levels the BCO5 biomass is unlikely to change much over the next 10 years.
- Bycatch and ecosystems - Stable: No major changes are expected to byatch and ecosystem risk scoring.
- Management systems - Improving: A National Blue Cod Strategy is currently being developed through Ministry for Primary Industries which may result in fishery specific objectives.