http://apsoi.org/sites/default/files/documents/meetings/SC-03-INFO-10%20Assessment%20of%20orange%20roughy%20stocks%20SIOFA%20Areas%201%2C%202%2C%203a%20and%203b.%20PRESENTATION.pdfThe SIODFA fishery in the Southern Indian Ocean consists of two major fisheries:
A (austral) winter spawn fishery for orange roughy and
A year-round fishery for alfonsino.
In addition to the two major targeted fishery, a range of bycatch species are retained, some of which are of relatively high value, e.g. boarfish/armourhead. Retained bycatch species include:
Oreos (Black Oreo [Allocyttus niger], Smooth Oreo [Pseudocyttus maculates] and Spiky Oreo [Neocyttus rhomboidalis]) NZ: OEO;
(Black) Cardinal fish (Epigonus telescopes) NZ: CDL
Bluenose warehou (Also called Antarctic butterfish) (Hyperoglyphe antarctica) NZ: BNS; Aust: BWA
Blue Eye Trevalla; Indian Ocean Trevalla (Schedophilius labrynthica) Aust: TBE,BYS
Oilfish (Ruvettus pretiosus)
Boarfish (Pelagic armourhead) (Pentaceros richardsoni). Aust:EDR
Rubyfish (Plagiogeneion rubiginosus) NZ: RBY
Ribaldo (Mora moro) NZ: RIB
Wreckfish, Groper (Oxyprion spp.) NZ: HPB;
Ray’s bream (Brama brama: Bramidae)
Black gemfish/black scabbardfish (Nesiarchus nasutus)(BGF)
Effective fishery management requires certain actions no matter size of the fishery:
Data must be collected on the amount of catch, fishing effort, locations of catch and biological information (fish sizes, sex, status of gonads, age, etc.): this date must be analyzed and reported in a competent and timely manner.
Resource status must be assessed: what is the biomass – at a minimum is it stable, being depleted or increasing?
What is the status of the spawning biomass of the stocks being examined? This provides one of the determinants of subsequent potential recruitment success.
How much fish should be harvested or at least, what level of effort should be permitted in the fishery?
Are particular conservation measures required, e.g. closed seasons, closed areas, minimum fish sizes, protection of associated or dependent species or discarded bycatch species, etc.?
This process usually proceeds on an annual basis and for international fisheries requires the cooperation of the various flag states that are involved and the funding of working groups to undertake the required analyses in an appropriate environment of trust and confidentiality.
In the case of orange roughy, much work has been done on the population biology of this species in Australia and New Zealand, and to a lesser extent elsewhere. In the SIO a first challenge is to determine what biomass of orange roughy exists and its population structure. Also important, but really a challenge of ‘forensic’ fisheries science is trying to determine the unfished stock sizes of the various populations prior to the start of fishing. This would give an idea of the potential long-term productivity of the stocks in question. However, data are not available for most of the vessels that participated in the fishery during its Klondike days of 2000 – 2002 and funding needs to be found to support indirect methods as well as interviewing past participants in the fishery. Related to this will be the cost-benefits of this activity, given that a wide range of research activities remain to be addressed. The first stock assessment by the Stock and Risk Assement was of orange roughy (1st Meeting of SIOFA SAWG (Stock Assessments Working Group), 15-18 March 2018, Saint Denis, La Reunion), Assessments of orange roughy stocks in SIOFA statistical areas 1, 2, 3a, and 3b by Patrick Cordue of Innovative Solutions Ltd.
For the retained bycatch species, many make relatively minor contributions the fishery, but should still remain of interest to the assessment biologist. Cardinalfish, boarfish and bluenose warehou are at times important and valuable components of the catch – when they are encountered. Other bycatch species may be taken incidentally, e.g. certain oreos, by skippers less skilled in identifying them on their echo sounders and so enabling the vessel to avoid catching them in the trawl.
SIODFA vessels have collected an enormous amount of biological information on the population biology of commercial species they catch consisting of length and weight frequencies, sex and gonad condition data and otoliths for aging purposes.
SIODFA operators believe that because of the small scale, ‘boutique’, nature of the fisheries, traditional methods that are dependent on fishery- independent surveys and research will never be cost-effective for the SIO and thus will never be undertaken. Rather, SIODFA believes that the industry must play the leading role in the collection of data and perhaps even its initial, if not complete, analysis. One particular example of industry-lead research is that of aggregation-based commercial-vessel acoustic fish-stock assessment surveys. Considerable effort has been directed in this activity and certain SIODFA members can be considered leaders in this developing and applying this technique. All SIODFA vessels are equipped with SIMRAD ES60 acoustic systems capable of undertaking scientifically-calibrated acoustic surveys. Indeed, two SIODFA associates participated in the December 2009 FAO workshop that produced the “Report of the Workshop on Fishing Vessel Execution of Acoustic Surveys of Deep-sea Species: Main Issues and Way Forward”,FAO Fisheries and Aquaculture Circular No.1059.
The vulnerability of orange roughy to overfishing is (now) well known, and SIODFA operators are aware that their fishing effort should not result in a fishing mortality that exceeds this species very low natural mortality. This emphasizes the extremely important issue of ensuring that the fleet fishing capacity targeting this species does not exceed that required to take the sustainable yield. For this reason, SIODFA operators have committed themselves to capping their fishing effort at the existing level, which is four vessels.
It is stressed that as an industry association, SIODFA has no enforcement powers over non-member operators and in the case of its own members, compliance with Association agreements is based solely on a shared vision of what is required to ensure responsible fisheries management and a sustainable fishery.
All SIODFA members have experience in operating in countries where the fisheries management regimes use strong forms of property rights that promote effective management of their fisheries. This long exposure to this evidently successful method of fisheries governance provides a solid basis for their support for such rights-based fisheries management of high seas stocks, It is the view of SIODFA that in the case of the Southern Indian Ocean deep-sea fisheries, endowing the operators with secure fishing entitlements would be the most effective way to provide the incentives to ensure effective fisheries management: it would remove existing perverse incentives and follow the examples set in the most successful fisehries management regimes existing today.
On a tactical level, dedicated working groups need to be established and funded to address management of (a) orange roughy, which has the advantage that much scientific work has been undertaken in Australian and New Zealand that should provide much guidance in the case of the Southern Indian Ocean, (b) alfonsino, which though a nearly-global high seas fishery its management requirements remain yet to be addressed (c) the more important retained bycatch species such as boarfish, bluenose warehou and other Centrolophidae and (d) all other bycatch species. In terms of discarded bycatch species, funding is required to establish a working group to address the issue of deepwater sharks.