Geographical Range Extension of the Spotfin burrfish, Chilomycterus reticulatus (L. 1758), in the Canary Islands: A Response to Ocean Warming?

Abstract

In recent decades, numerous marine species have changed their distribution ranges due to ocean warming. The Spotfin burrfish, Chilomycterus reticulatus, is a reef fish with a global distribution along tropical, subtropical and warm-temperate areas of the Pacific, Indian and Atlantic oceans. In this work, we analyzed the presence of this species, between 1990 and 2019, at two islands of the Canarian Archipelago under varying oceanographic conditions: El Hierro (the westernmost island, under more tropical conditions) and Gran Canaria (a central-east island, under more cooler conditions). We expected that, under increased ocean temperatures in recent decades, the number of sightings has increased in Gran Canaria relative to El Hierro. We compiled information from different sources, including interviews and local citizenship databases. A total of 534 sightings were reported: 38.58% from El Hierro and 61.43% from Gran Canaria. The number of sightings on Gran Canaria has significantly increased through time, at a rate of 0.1 sightings per year; at El Hierro, however, the number of sightings has not significantly changed over time. Sea Surface Temperature has linearly increased in both El Hierro and Gran Canaria islands over the last three decades. Positive Sea Surface Temperature anomalies, particularly in 1998 and 2010, including high winter minimum temperatures, provide an ideal oceanographic context to favour the arrival of new individuals and, consequently, the increase in the number of sightings in Gran Canaria. Still, potential donor areas of fish recruits remain unknown.

Further Advance of Gambierdiscus Species in the Canary Islands, with the First Report of Gambierdiscus belizeanus

“…Therefore, a priori, the west could be more suitable for the warmer tropical species. This phenomenon has already been observed in fish [49]. Overall, the range of SST during 1972-2012 in the Archipelago was 15.9 • C in March-April and 25.5 • C in August-October [50].…”

Expanding north: first record of the beaded sea cucumber Euapta lappa at Madeira Island

“…However, studies investigating the benthic communities at the Canary Islands describe an eastern-to-western gradient concerning the E. lappa abundance, with usually higher densities encountered at the western islands of the archipelago (Hernández et al ., 2013). In the past, this trend was also observed for other species with tropical affinities, such as the spotfin burrfish Chilomycterus reticulatus or ephemeral benthic algae species (Sangil et al ., 2012; Espino et al ., 2019). This imbalance in observations of certain tropical species most likely follows the prevailing temperature gradient in the Canary Islands, with western islands being slightly warmer than eastern ones (Barton et al ., 1998; Sangil et al ., 2012).…”

Higher daily temperature range at depth is linked with higher thermotolerance in antipatharians from the canary islands

“…SST trends vary from +0.16°C (Siemer et al, 2021) to +0.5°C per decade (Demarcq, 2009), according to the period and data source (Table 1). Increasing temperatures across the archipelago has already resulted in biogeographical shifts, with the arrival of tropical species and the expansion of thermophilic endemic species around several islands (Brito et al, 2014(Brito et al, , 2017Espino et al, 2019).…”