6.1 Fishery statistics and biological data
6.2 Biology and stock assessment
Finally the Group considered the improvements in the fields of data collection and reporting, as well as of investigations on the biology and dynamics of cephalopod stocks, which condition their better assessment and ultimately their rational utilization. In that context, it identified a list of priority tasks for which it made the following recommendations:
(i) All countries (see sect. 4.1)catching appreciable quantities of cephalopods should report their catch and effort statistics with the details required by the CECAF statistical system, i.e. by species groups (octopus/cuttlefishes/squids) and statistical divisions (Morocco/Sahara Coastal/Cape Verde);
(ii) The major fishing countries (Spain, Korea, Japan) should endeavour to collect their catch and effort statistics by main fishing grounds, i.e. to gather separate data for each of the following sectors: 13° - 15°, 15° - 19°, 19° - 22° and 22° - 26° lat. N;
(iii) Considering the importance for stock assessment of the information concerning the early stages of a fishery, Senegal should ensure that all participants to the fishery collect and submit appropriate statistics and biological data on its newly developing cephalopod fishery;
(iv) Standards for the measurement of cephalopods should be defined following the procedures described in section 3.4 of the present report.
(i) Studies on the biology (especially on age determination and growth, distribution and migrations, spawning, etc.) of cuttlefishes and squids should rapidly be strengthened;
(ii) The 1975, 76 and 77 Spanish length distributions should be rapidly analyzed by Spanish scientists to clarify the growth pattern of octopus and, hopefully, to undertake cohort analysis and simulations along the lines described in section 3.1 and 3.2.
(iii) The possible losses of tags in octopus and their irregular reporting by fishermen, particularly of nationalities other than Spain, should rapidly be investigated. Assuming that these questions can be properly solved an intensive, but of short-term duration, tagging campaign should be undertaken, primarily to clarify the growth pattern of the main cephalopod species as well as their distribution and migration patterns (Canary Laboratory of the Spanish Institute of Oceanography).
(iv) Investigations on the selectivity of the three species groups of cephalopods should be intensified;
(v) The results of the resource surveys conducted by Spain in the area during the present decade should be thoroughly analyzed, in particular in order to estimate and compare biomass indices.
Finally, the Group stressed that regular meetings, such as this one, and regional collaboration in general, are essential for the development of the biological studies on cephalopod stocks and for the routine monitoring of their state of exploitation.
