A scientific project began to gather information on marine life in Tierra del Fuego, focusing on chondrichthyans on the island. The goal is to know what species are on the Atlantic coast to understand their conservation status and their management.
During January and February, a team of scientists from CADIC and the Por el Mar Foundation conducted a survey on sharks, rays, and chimeras and their relationship with kelp forests.
“The results were really very encouraging,” detailed Matías Delpiani, a marine biologist from the Laboratory of Ecology, Physiology, and Evolution of Aquatic Organisms at CADIC/ICPA-UNTDF.
During the campaigns, two species of sharks (spiny dogfish and small-spotted catshark), two species of rays (longnose skate and marbled ray) and one chimera, the roosterfish, were recorded.
“This finding is very important because it involves the first coastal captures made for research purposes in this area,” he emphasized.
On the other hand, Ramiro Braga, a biologist from the Por el Mar Foundation explained: “The objective of this campaign was to begin recording the diversity of chondrichthyans with a special emphasis on specimens associated with the giant kelp forests Macrocystis pyrifera of the intertidal zone and its surroundings. In conservation there is a clear premise: you cannot protect what you do not know,” he added.
An intriguing fact emerged immediately and raised new questions: “all the captured specimens are females,” noted Delpiani.
With the samples being analyzed together with CADIC, the team seeks to reconstruct basic aspects of their life history on the island: how they use the habitat, whether there might be breeding areas, what they feed on, in what reproductive stage they are, and what the proportion of males and females in these populations is.
This knowledge is relevant because sharks play a central ecological role. Delpiani explained that they act as “apex predators or mesopredators,” regulating populations and maintaining the balance of food webs.
But he also emphasized that they are particularly vulnerable animals: “the greatest threats are overfishing and bycatch,” and he recalled that “they grow slowly, mature late, and have few offspring,” which makes their recovery difficult when the fishing pressure is high.
To organize the campaign, the team relied on the experience of artisanal and sport fishermen from the area. “The information provided by fishermen helped us enormously.
They know these environments like the back of their hand. They are essential actors and of great help for our research,” said Braga.
Based on this data, they were able to define sampling points, work times, and organize two scientific campaigns with specific local information, something especially valuable in a topic with so few precedents on the island.
The fieldwork also required adapting to the specific conditions of that coast. Unlike the Beagle Channel, in the Fuegian Atlantic there is a very large tidal range and a strong predominance of winds, so the operation was largely conditioned by the tide regime.
“We had to set the fishing gear during low tide so that it would work with the high tide,” detailed Ramiro Braga, noting that it is an open sea environment, more energetic, where navigation is not as frequent as in the channel.
Braga also highlighted the importance of understanding these species in Tierra del Fuego considering that the link with the sea is both social and economic.
“Artisanal fishing is much more than a trade: it is the livelihood of numerous families and an activity deeply linked to the history of coastal communities,” he noted. In this context, he emphasized the key role that fishermen can play in generating knowledge about sharks, rays, and chimeras.
From their daily experience at sea, they can provide valuable information to improve the record of catches, recognize the species present, and collaborate in the care of the more sensitive ones.
“The joint work between fishermen and researchers allows for a better understanding of the marine ecosystem and to think of strategies that support both conservation and the continuity of this historical activity,” he explained.
The expedition is just a first step. On an island where there are still more questions than answers regarding chondrichthyans, each record adds a piece to understanding how these ecosystems function.
“Starting to know which species inhabit these environments and how they use them is the basis for any conservation strategy,” the researchers agree.
