Establishing an industry recovery strategy for the Area 3 zone of the Western Australian Abalone Managed Fishery
Trials of oceanographic data collection on commercial fishing vessels in SE Australia
Australia’s fisheries span a large area of ocean. Australia has the world’s third largest Exclusive Economic Zone (EEZ), with an area of over 8 million km2. This zone contains mainly Commonwealth managed fisheries, with State jurisdictions mainly in coastal waters up to the 3 nautical mile limit. Australia's total wild-catch fisheries gross value of production is $1.6 billion, of which 28% is from Commonwealth fisheries and 72% from the smaller coastal inshore fisheries managed by state jurisdictions. The wildcatch fisheries sector employs about 10,000 people across Australia (https://www.awe.gov.au/abares/research-topics/fisheries/fisheries-and-aquaculture-statistics/employment).
The commercial fishing industry has a network of thousands of vessels working mainly in inshore waters around Australia. They can supply a potential platform for extensive and fine scale spatial and temporal monitoring of the waters of the continental shelf (0-1200m), from the surface to the ocean floor. Given that their livelihoods depend on it, they have a keen understanding of oceanographic conditions with respect to fish behaviour, feeding and spawning and the various oceanographic factors that may influence this. In some fisheries (e.g. surface tuna longlining), fishers eagerly seek and use readily available fine-scale oceanographic data such as sea surface temperature and sea level, to improve their targeting and achieve higher resultant catch rates. For many other fisheries, however, it is the fine-scale sub-surface oceanographic conditions (feed layers, thermoclines, temperature at depth etc) that have a critical influence on their fishing dynamics. Unfortunately, this type of oceanographic data is far less readily available. Although fishers and scientists know these factors are important, the time series of fine scale spatial and temporal data relevant to fishery operations is not available to include in stock assessments. As a result, it is often assumed that variations in catch rates reflect changing stock abundance, when it may simply be a result of changing oceanographic conditions.
Marine scientists collect a vast range of oceanographic data using satellites, subsurface drones, and static and drifting buoys. Sea surface data, however, is much easier and more cost-effective to collect at high spatial and temporal resolutions than sub-surface data. Hence, understanding of sub-surface oceanographic conditions tends to be derived from modelling more than actual measurement. This may be sufficient at a wide-scale global or continental level, but it is not adequate at the fine-scale spatial and temporal resolution required for fisheries management.
The use of commercial fishing gear as a research data platform has been increasing in popularity internationally (https://www.frontiersin.org/articles/10.3389/fmars.2020.485512/full). A number of groups in Europe have been doing this for a decade (e.g Martinelli et al 2016), and New Zealand are also now involved (https://www.moanaproject.org/te-tiro-moana). However, this approach has yet to be implemented in Australia in a coordinated way. In particular, our approach dictates open access data served through the IMOS Australian Ocean Data Network (www.aodn.org.au) that can be collected once and used many times.
In this project we intend to instrument seafood sector assets (e.g Trawl Nets, longlines, pots) with fit-for- purpose quality-controlled (QC'd) temperature/pressure sensors to increase the sub-surface temperature data coverage around Australia’s shelf and upper slope regions (0-800m) at low cost. Not only will this assist in the collection of data at relevant spatial and temporal scales for use by fishers, but it will also provide a far more extensive level of QC’d data to oceanographers in near real time (NRT) for evaluation and ingestion into data-assimilating coastal models that will provide improved analysis and forecasts of oceanic conditions. In turn, this will also be of value to the fishing sector when used to standardise stock assessments.
Martinelli, M., Guicciardi, S., Penna, P., Belardinelli, A., Croci, C., Domenichetti, F., et al. (2016). Evaluation of the oceanographic measurement accuracy of different commercial sensors to be used on fishing gears. Ocean Eng. 111, 22–33. doi: 10.1016/J.OCEANENG.2015.10.037
Article
Implementation of dynamic reference points and harvest strategies to account for environmentally-driven changes in productivity in Australian fisheries
Effects of climate change and habitat degradation on Coral Trout
Evaluating the Effects of Seismic Energy on Pinctada maxima Pearl Oysters
Recent studies into the effects of seismic energy on molluscs have demonstrated a number of cumulative and sub-lethal impacts that indicated impairment of immune systems, cellular damage and adverse changes in behaviour. In scallops, cumulative exposure to seismic energy resulted in increased rates of mortality after 120 days (R Day et al. (2017)). These findings are of critical importance to the pearling industry, which relies on the harvest and husbandry of pearl oysters in coastal shelf water . Pearl oyster crops are typically 2 years duration, so long term effects will have a chronic sub-lethal effect on pearl production. In addition, as the oysters were still not fully recovered at the day 180 sampling, there is concern that the long recovery time may result in a reduction of the reproductive output for up to one year. Energetically compromised oysters will have a reduced reproductive output, and a higher proportion of male oysters, as egg production is more energy intensive.
This would have major ramifications for recruitment into the wildstock pearl oyster fishery and the pearling industry it underpins.
To these ends it became apparent that a 4th sampling round was critical in order to provide a condition data from the oyster sample set after 360 days; so that the responses of the oysters to seismic treatment may be better understood after the completion of one year – bearing in mind that at different times of the year oysters do different things.
The overarching objective of this experiment is to measure the impact of seismic surveys on wild harvested pearl oysters in a way that provides information that is useful to stakeholders in the pearl production and oil and gas industries and to the managers of these resources. The uncertainty surrounding the long-term impacts of seismic surveys on the health of pearl oysters and their pearl production capacity is the key driver of this study.