Floating objects of the eastern pacific: types, spatial distribution and temporal changes

Abstract

Palabras clave: objetos flotantes de origen terrestre, dispositivos agregadores de peces, Pacífico oriental, pesca de atún, zona epipelágica. http://dx.doi.org/10. 7773/cm.v27i3.473 Los objetos flotantes también pueden originarse en el ecosistema marino, como es el caso de cadáveres de ballenas, leones marinos, focas, etc. Organismos de natación lenta, como el tiburón ballena (Rhincodon typus), también han sido considerados objetos flotantes ABSTRACTThe spatial pattern was analyzed of different types of floating objects associated with the tuna fishery in the eastern tropical Pacific (ETP). Of the 34 types of floating objects, four classes were defined: floating objects of terrestrial origin (FOTE), floating objects of marine origin (FOMA), artificial floating objects (FOA), and fish aggregating devices (FAD). The information source was the observer database of the Inter-American Tropical Tuna Commission, for 1987 to 1997. The records of floating objects and fishery effort directed at them were analyzed, spatially and seasonally. The encounter rate and proportion per class were estimated, by one-degree quadrants. Spatial models were obtained for these variables using non-parametric regression. Before 1993, the encounter rates and proportion of FOTE were the most important, located close to the Central American coast. After that year, the region to the west of the Galapagos Islands was the most important. Since 1994, a spatial expansion of the floating objects fishery is observed to the southwest of the ETP, with the use of FAD. FOMA were found to concentrate in two zones: one off the coasts of Ecuador and Peru, and the other off Baja California, Mexico. The spatial patterns of the types of floating objects indicate a seasonal variation. It was concluded that the ETP can be divided into three zones: one coastal and two offshore zones. FOTE dominate in the coastal zone and to the north of the Equator, whereas FAD are the most important in the zone south of the Equator.

Using a Partial Sum Method and GPS Tracking Data to Identify Area Restricted Search by Artisanal Fishers at Moored Fish Aggregating Devices in the Commonwealth of Dominica

“…Drifting logs, timbers, marine litter such as plastic objects and polystyrene foam, lost fishing gear, and Sargassum sp. (a type of seaweed) will also attract fish into patches [ 46 ]. Birds are also present at these wood patches.…”

Incidental catch of the rare shortbill spearfish (Tetrapturus angustirostris) by the tuna purse seine fleet in the eastern tropical Pacific Ocean

“…Some authors suggest that floating objects tend to aggregate around certain oceanographic structures, such as fronts and gyres, where billfish prey also congregate (Sakagawa 1989, cited in Sosa-Nishizaki 1998. Solana-Sansores (2001) showed that the equatorial current system can retain floating objects from different origins in a latitudinal band from 15ºS to 10ºN and noted that that purse seine sets on floating objects are becoming more common. This could explain the high incidental catch of spearfish on this type of set, which occurs durante esa temporada del año.…”