SELEKTIVITAS ALAT TANGKAP PUKAT CINCIN (PURSE SEINE) DI PERAIRAN PASONGSONGAN SUMENEP

The low profits of mini purse seine in Sathean Village will have an impact on the business risks being carried out. The new paradigm states that the relationship between risk and profit levels is quadratic; too much risk can lead to the loss and even destruction of a business. Thus, the fisherman of mini purse seine business owners in Sathean Village needs to manage their business risk well to achieve optimum profit for business sustainability. This study aims to assess business profits and business risks. Primary data was collected on 6 fisherman owners of mini purse seine business owners in Sathean Village as respondents, conducted business profit analysis and business risk calculation based on probability density. The results showed that the business profit was Rp 241,608,203/year or Rp 196,551,994 in the peak season, Rp 41.828.721 in the medium season and Rp 3.2227.488 in the less season.In peak and less seasons, these businesses are at risk or have the opportunity to lose, while in the medium season is not risky.

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Quantifying the increase in fishing efficiency due to the use of drifting FADs equipped with echosounders in tropical tuna purse seine fisheries

ICES Journal of Marine Science ◽

10.1093/icesjms/fsaa216 ◽

2020 ◽

Author(s):

Gwenaëlle Wain ◽

Loreleï Guéry ◽

David Michael Kaplan ◽

Daniel Gaertner

Keyword(s):

New Technology ◽

Recent Change ◽

Purse Seine ◽

Catch Per Unit Effort ◽

Katsuwonus Pelamis ◽

Thunnus Obesus ◽

Efficiency Increase ◽

Tropical Tuna ◽

Floating Objects ◽

The Impact

Abstract Numerous pelagic species are known to associate with floating objects (FOBs), including tropical tunas. Purse seiners use this behaviour to facilitate the capture of tropical tunas by deploying artificial drifting fish aggregating devices (dFADs). One major recent change has been the integration of echosounders in satellite-tracked GPS buoys attached to FOBs, allowing fishers to remotely estimate fishable biomass. Understanding the effects of this new technology on catch of the three main tuna species (yellowfin tuna, Thunnus albacares; bigeye tuna, Thunnus obesus; and skipjack tuna, Katsuwonus pelamis) is important to accurately correct for this change in catch-per-unit-effort (CPUE) indices used for stock assessments. We analysed catch data from the French purse seine fleet for the period 2010–2017 in the Indian Ocean to assess the impact of this fleet’s switch to echosounder buoys around 2012. Results indicate that echosounders do not increase the probability a set will be succesful, but they have a positive effect on catch per set, with catches on average increasing by ≈2−2.5 tonnes per set (≈10%) when made on the vessel's own dFADs equipped with an echosounder buoy. Increases were due to a decrease in sets below ≈25 tonnes and an increase in those greater than ≈25 tonnes, with a non-linear transition around this threshold. This increase explains the considerable investment of purse seiners in echosounder buoys, but also raises concerns about bias in stock size estimates based on CPUE if we do not correct for this fishing efficiency increase.

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