A Spotted moray (Gymnothorax moringa), at the bottom of the frame, surrounded by a shoal of Tomtate grunts (Haemulon aurolineatum), Sea chubs (Kyphosus spp.), and Horse-eye jacks (Caranx latus), with one Squirrelfish (Holocentrus adscensionis), at Saco da Banana near "Snake Island", properly called Ilha da Queimada Grande. Credit: LabecMar-UNIFESP
The study is reported in an article published in the journal Marine Environmental Research.
The main finding is the upper boundary of the mesophotic zone, the "middle light" region between the brightly lit ocean surface and the darkest depths. The lower limit of the mesophotic zone is the furthest that sunlight can penetrate the ocean.
Previous studies put the upper limit of this zone at a depth of 30 m, but the authors' measurements of light penetration and fish inventories showed it to lie at a depth of between 15 m and 18 m in the subtropical coastal region.
"Besides the amount of light, which at this depth is only 10% of surface light incidence, we detected different fish fauna, as well as species that circulate between the shallow and mesophotic zones," said Maisha Gragnolati, first author of the article. The study was conducted while she was researching for a master's degree in biodiversity and marine and coastal ecology at the Institute of Marine Sciences (IMAR-UNIFESP) in Santos (São Paulo state, Brazil).
According to the researchers, the gap between the classical definition widely found in the scientific literature (30 m) and their finding (18 m) is due to the fact that most previously published studies were…
A Spotted moray (Gymnothorax moringa), at the bottom of the frame, surrounded by a shoal of Tomtate grunts (Haemulon aurolineatum), Sea chubs (Kyphosus spp.), and Horse-eye jacks (Caranx latus), with one Squirrelfish (Holocentrus adscensionis), at Saco da Banana near "Snake Island", properly called Ilha da Queimada Grande. Credit: LabecMar-UNIFESP
The study is reported in an article published in the journal Marine Environmental Research.
The main finding is the upper boundary of the mesophotic zone, the "middle light" region between the brightly lit ocean surface and the darkest depths. The lower limit of the mesophotic zone is the furthest that sunlight can penetrate the ocean.
Previous studies put the upper limit of this zone at a depth of 30 m, but the authors' measurements of light penetration and fish inventories showed it to lie at a depth of between 15 m and 18 m in the subtropical coastal region.
"Besides the amount of light, which at this depth is only 10% of surface light incidence, we detected different fish fauna, as well as species that circulate between the shallow and mesophotic zones," said Maisha Gragnolati, first author of the article. The study was conducted while she was researching for a master's degree in biodiversity and marine and coastal ecology at the Institute of Marine Sciences (IMAR-UNIFESP) in Santos (São Paulo state, Brazil).
According to the researchers, the gap between the classical definition widely found in the scientific literature (30 m) and their finding (18 m) is due to the fact that most previously published studies were…
André Julião
phys.org