Miguel Machete

IMAR Marine and Environmental Research Centre | IMAR-CMA · Department of oceanography and fisheries

The multispecific and highly dynamic nature of pelagic longline fisheries demands a holistic view that will likely benefit the development of effective management strategies. This study aims to provide an integrated perspective of the Portuguese longline fishery targeting swordfish Xiphias gladius and blue shark Prionace glauca in the Northeast Atl...

Incidental catch or bycatch of sea turtles by pelagic longline fisheries is a major concern worldwide. The Northeast Atlantic hosts key foraging and developmental areas for oceanic juvenile loggerhead sea turtles (Caretta caretta) originating mainly from the Southeastern USA and Cape Verde. This region may be one of the most heavily fished areas by...

Abstract In 2022 Biosphere Expeditions concluded its 16th year of cetacean photo-identification and distribution studies in the Azores, after a two-year break for COVID-19. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 21 March to 21 Apr...

Fisherman have known and explored the association between tuna and whale sharks for centuries. Just as in the past, present day industrial fishers search for the presence of whale shark as cue to locate tuna schools. These whale shark-tuna associations have been usually assumed to result from the same ecological drivers that govern the attraction o...

Abstract In 2019 Biosphere Expeditions concluded its 15th year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 29 March to 18 April and concentrated on six main proj...

After hatching, juveniles of most sea turtle species undertake long migrations across ocean basins and remain in oceanic habitats for several years. Assessing population abundance and demographic parameters during this oceanic stage is challenging. Two long-recognized deficiencies in population assessment are (i) reliance on trends in numbers of ne...

Abstract In 2018 Biosphere Expeditions concluded its fourteenth successful year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 8 March to 19 April and concentrated...

In contrast to the vast majority of European maritime territories, the Azores is an isolated oceanic archipelago in the North East Atlantic characterised by small-scale hooks-and-lines fisheries. Yet, in spite of the low environmental impact of such fishing gears, there is no solid integrative information on the discard practices. This study bridge...

The distribution and composition of macro litter floating around oceanic islands is poorly known, especially in the North Atlantic. Due to its isolated location at the fringe of the North Atlantic subtropical gyre, the Azores archipelago has recently been proposed as a potential retention zone for floating litter. To further investigate this assump...

Small-scale artisanal fisheries can have a significant negative impact in cetacean populations. Cetacean bycatch has been documented in the pole-and-line tuna fishery in the Azores with common dolphins being the species more frequently taken. Based on data collected by observers on ∼50% of vessels operating from 1998 to 2012, we investigate the inf...

Estimates of common dolphin bycatch for the bigeye tuna fishery from 1998–2012.

Abstract In 2016 Biosphere Expeditions concluded its thirteenth successful year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 4 April to 5 May and concentrated on...

The Azores is a group of islands located in the NE Atlantic that is largely dependent upon its marine resources. As for most oceanic islands, fishing has always been a key driver of the local Azorean economy. The Azorean fishing industry is a multi-segmented sector, targeting multiple species with a wide range of fishing gears and methods that can...

Marine spatial planning and ecological research call for high-resolution species distribution data. However, those data are still not available for most marine large vertebrates. The dynamic nature of oceanographic processes and the wide-ranging behavior of many marine vertebrates create further difficulties, as distribution data must incorporate b...

Abstract In 2015 Biosphere Expeditions concluded its twelfth successful year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 6 to 27 April 2015 and concentrated on s...

Abstract In 2014 Biosphere Expeditions concluded its eleventh successful year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 7 April to 10 May and concentrated on s...

Abstract In 2013 Biosphere Expeditions concluded its tenth year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 8 to 29 April 2013 and concentrated on six main proje...

Abstract In 2012 Biosphere Expeditions concluded its ninth successful year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 2 April to 5 May 2012 and concentrated on...

Abstract In 2011 Biosphere Expeditions concluded its eighth successful year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 4 to 25 April and concentrated on six mai...

Abstract In 2010 Biosphere Expeditions concluded its seventh successful year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the island of Faial and work was conducted around the three islands of Faial, Pico and São Jorge. The expedition ran from 3 April until 10 May 2010 and concentrat...

In 2006 Biosphere Expeditions concluded its third successful year of cetacean photo-identification and distribution studies in the Azores. The expedition was based in Horta on the Island of Faial and work was conducted around three islands of Faial, Pico and São Jorge. The expedition ran from 17 April until 27 May and concentrated on six projects....