The last few months have seen several reports in local and international press of dead birds on beaches of central Chile. Specifically, a mass mortality of sea birds was recorded in May on the shores of the town of Rocas de Santo Domingo. The first reports mentioned some 2,000 dead seabirds within four miles of this coastal city.
The cutting below shows an example of local press coverage of the mass mortality event
The total number of dead birds eventually arrived at the figure of 5,600. Among the species affected were the Peruvian booby, Peruvian pelican, Rock cormorant, Kelp gull and Sooty shearwater. This last species was the most affected registering a mortality of 4,454 individuals according to a report by José Luis Brito Montero, director of the Museum of Natural Science and Archaeology of the City of San Antonio.
The causes of this mass mortality event suggest interaction with purse seine fishing fleets operating in the area, mainly artisanal vessels, which target sardines and anchovies. As pointed out by Jose Luis Brito Montero in his report:
"Although this situation is accidental and due to an unfortunate situation that does not occur constantly, we know that during fishing activities there are always cases of incidental seabird mortality, but in low numbers. This new case is the cumulative result of several elements that occurred simultaneously: oceanographic conditions, presence of large numbers of anchovies off the coast, fishing activity targeting the anchovy at the same time as the northerly migration of sooty shearwaters, the species most adversely affected in this case."
The ATF in Chile conducted exploratory trips on board purse seine vessels during the second half of 2011. We performed four exploratory trips, which allowed us to confirm the existence of interactions between purse seine operations and seabirds. This exploratory study marked the beginning of one of our main objectives in Chile: working with the fishing industry to record how these mortalities occur and look for potential mitigation measures to prevent it in the future.
The image below shows a typical artisanal purse-seine vessel off the Chilean coast.
Our work gained recognition from the Undersecretary of Fisheries, who invited us to work together with fishing associations of San Antonio, a port city with a strong artisanal purse seine fleet which has been involved in recent events of seabird mortality.
Finding a solution to mitigate the incidental catch of seabirds in this fishery is not an easy challenge. Globally, this problem has been poorly addressed. There are precedents in purse seine fleets of Argentina, Uruguay, Spain and New Zealand.
However, much remains to be evaluated before this is fully understood. We are working toward finding solutions that may be developed across South America and the world, but it is necessary to take the first steps before you solve any problem!