Evaluation des paramètres biologiques et essai de la réduction des pertes post-capture des langoustes Palinuridae dans les villages d’Ampasimasay et de Maroroy (Région Anôsy)

Abstract

The Anôsy region is rich in fishing resources, particularly lobsters. Lobster fishing
is one of the main economic activities in the region, contributing to improving the
livelihoods of the local population. The objective of this study is to understand the biological
characteristics of lobsters in this region and to evaluate post-harvest losses. Data collection
occurred in two phases: the first, between October and December 2019, focused on studying
the characteristics of the catch population and identifying causes of post-capture loss. The
second phase took place from December 2020 to April 2021, aiming to conduct an
experiment to reduce post-capture losses. The methodology involved monitoring fishing
activities through surveys and interviews with key informants and local stakeholders,
followed by improvements to the current technique to reduce post-harvest loss. The study's
findings reveal that lobsters were exclusively captured using trap fishing gear in shallow
waters ranging from 1.5 to 18 meters in depth. Currently, resources are relatively low, with
an average CPUE of 0.17 kg/trap/day. Over a three-month monitoring period, a sample of
1474 individuals were collected. The Panulirus homarus species dominates over other
lobster species in this area, attributed to habitat structure and food sources. The study
population exhibits a prevalence of females compared to males. The size at which lobsters
reach functional maturity is below the legal minimum capture size, as LCT50 is 4.75 cm,
where the regression lines of mature and immature specimens intersect. The relationship
between LCT and weight shows a negative allometry (b < 3) for both sexes. Fishermen's
products are packaged in various ways: bulk, netted, in sobika and in bags. Post-harvest loss
varies depending on the packaging type, indicating a significant difference between these
methods. Additionally, a significant difference was observed between local pond packaging
and the conducted experiment. The results obtained in this study contribute to lobster
resource management and provide a better understanding of post-harvest loss causes.
Biological data facilitate decision-making regarding sustainable resource management.