La mass death de peces in the fish farms located in front of Melenara, in TeldeThis has become one of the most controversial environmental incidents in recent times on the east coast of Gran Canaria. Thousands of tons of sea bass were found dead in the sea cages, prompting criminal investigations, technical inspections, and scientific analyses to try to clarify what really happened.
The institutional shift: aquaculture is, for the moment, out of the spotlight
The president of the Gran Canaria Island Council, Antonio Morales, has sought to establish a position in this complex scenario. In recent public statements, he recalled that the General Directorate of Fisheries of the Government of the Canary Islands carried out a specific inspection of the marine farms located off the coast of Teldeconcluding that the facilities are "in optimal condition" and that, according to that report, Aquaculture activity would not be directly responsible for the mortality episode.
This institutional statement This largely dispels the suspicion surrounding the aquaculture company., at least as far as the origin of the possible spillThe company had initially been at the center of the debate for being the main affected and the first to raise the alarm, but the preliminary conclusions of the Fisheries inspection, for now, absolve it of responsibility for the polluting incident.
Morales has insisted that it is essential clarify exactly what caused the spill that affected the fish in the cagesemphasizing that the report being prepared by the Environmental Prosecutor's Office must "make transparent what has happened." The repeated reference to an outfall pipe near the facilities has led many to focus their attention on the sanitation infrastructure under municipal responsibility, although without explicitly naming any particular city council.
In practice, the political message is clear: If the aquaculture operation doesn't fail and it's maintained that there was a spill, someone will have to take responsibility for what happened to that outfall....what condition it was in and why it ended up affecting the cages. All this, pending official conclusions.
The initial complaint and the economic consequences
The public origin of this case lies in the complaint filed by the aquaculture company AquanariaThe company, which operates sea cages off the coast of Melenara and other points along the Telde coast, notified the authorities of the presence of a spill "strange and chemical-looking" originating from an emissary near their cages, which would have triggered a mass die-off de peces.
According to the company, Around 2.500 tons of sea bass died, with economic losses estimated at around 30 millones de eurosThe magnitude of the damage forced the activation of precautionary protocols on the coast, with the temporary closure of several beaches from the municipality of Telde and other areas of the eastern coast of Gran Canaria, while water and sand samples were being analyzed.
As a result of that complaint, the The Las Palmas Environmental Prosecutor's Office opened proceedings on October 17with the aim of determining the cause, origin and possible perpetrators of the spill. The Public Prosecutor's Office commissioned the Seprona of the Civil Guard the practice of the necessary investigations, and demanded the affected municipalities that they submit the results of the analyses carried out, as well as information on the closure and reopening of the bathing areas.
Meanwhile The environmental crisis moved into the political and social arena.With debates surrounding the impact of aquaculture on the Telde coast, the suitability of submarine outfalls, wastewater management, and the impact on the area's tourism image, and without a definitive explanation for the problem's origin, each new technical report has added nuances to a story that remains incomplete. impact on the tourist image It was one of the most debated effects in local forums.
Working conditions in cages: a complaint that raises eyebrows
Alongside the environmental and economic fronts, the case has opened another delicate flank: occupational safety and health management within fish farms in TeldeA professional diver, with a degree in Biology and Aquaculture, filed a formal complaint placing the Melenara sea cages and the Origin area (Tufia) at the center of an alleged repeated breach of occupational risk prevention regulations.
In that document, dated the 7th September 2025The complainant describes how the staff responsible for removing the high mortality rate de peces -sometimes, up to five tons of dead specimens per day- would have been forced to enter cages and handle corpses in an advanced state of decomposition, with direct contact with viscera and organic remains, without adequate personal protective equipment or specific training.
The complaint notes that these works were carried out in the weeks and months leading up to the major pollution episode in OctoberThis suggests that a significant mortality problem already existed in the fish farms of Melenara. In fact, the diver maintains that the episodes of mass withdrawal de peces The deaths would have been repeated in August and September, without biosecurity protocols being applied in accordance with the situation.
The aquaculture biologist claims that the company did not provide effective means of disinfection after handling corpsesnor would it have clearly communicated the risks associated with these tasks, nor proven the existence of a specific prevention plan against biological risks, despite it being a high-risk health activity.
Beyond the labor dispute, this complaint introduces a key element into the debate: the possible persistence of internal problems in the cages prior to the spill that the company attributes to an external originThe company, however, reportedly declined to comment on these previous deaths when contacted by the digital media outlet that brought the case to light.
Biological agents and risks to workers' health
One of the most sensitive points of the labor complaint is the identification of a specific biological agent in the work environment: Lactococcus sp., a zoonotic pathogen classified as Group 2 Biological Agent according Royal Decree 664 / 1997, which regulates the protection of workers against exposure to biological agents at work.
In accordance with applicable legislation, The presence of these types of microorganisms requires the activation of strict measures. risk assessment, information, training, provision of appropriate protective equipment and specific health monitoring of potentially exposed employees.
The complainant warns that prolonged, unprotected exposure to this pathogen could lead to serious clinical consequencesThese include endocarditis, bacteremia, abscesses, and osteoarticular infections, pathologies documented in humans associated with this group of biological agents. In their account, the lack of clear protocols and adequate equipment unnecessarily increased the health risk for workers.
According to your version, The company did not formally inform the staff about the extent of these risks.Nor would it have implemented a robust biosafety system despite repeated mortality incidents. The absence of a specific prevention plan against biological risks in a context of intensive handling de peces Deaths is one of the elements that, in his opinion, violates the basic regulations on occupational safety and health.
The document argues that this situation It would not be an isolated incident.but a practice maintained for at least three yearsThis would multiply the scope of the potential breach. If confirmed, it could lead to... serious administrative responsibilities due to the impact on occupational health and, ultimately, the overall management of mortality in cages.
The scientific response: a toxicological report that qualifies the account of the spill
As the Prosecutor's Office investigations progressed and complaints and statements accumulated, the Ministry for Ecological Transition and the Demographic Challenge commissioned a official toxicology report to the Clinical and Analytical Toxicology Service of the University of Las Palmas de Gran Canaria (ULPGC), with the aim of obtaining objective data on the possible presence of pollutants in the marine environment of Melenara.
The study, by 12 pages and dated December 4, 2025, analyzed 17 different samples Seawater (from the surface and the seabed), marine sediments, and sand from Melenara beach (north, center, and south zones), all collected outside the perimeter of the sea cages, were compared with liver and gill tissues from a Sea bass farmed indoors in aquaculture facilities.
The samples were sent by the Ministry to the ULPGC on November 11, 2025. in the midst of a crisis due to high mortality de peces in the fish farms of Melenara-SalinetasThe university laboratory was responsible for determining the presence of different organic and inorganic compounds both in the open marine environment and in the tissues of the fish from the cages.
Regarding the seawater samples -four deep and four surface, in different sectors of the area-, the results were negative results for almost all of the organic compounds analyzedNo substances were detected that pointed to an acute toxic episode or anomalous chemical contamination, with the parameters falling within ranges compatible with those of a typical urban coast.
In the case of marine sediments and beach sandThe report does identify the presence of polycyclic aromatic hydrocarbons (PAHs) -such as fluoranthene, pyrene, chrysene or benzo(a)anthracene-, although in low concentrations, considered typical of the Background pollution associated with the combustion of fossil fuels and maritime and land trafficExperts emphasize that these levels would not be capable of causing acute toxic effects on marine life.
Contaminants within fish: bioaccumulation and internal factors
The most striking contrast in the report appears when analyzing the biological samples of caged sea bassThe following were detected in the liver and gill tissues of the specimen from the aquaculture facilities: significantly higher concentrations of certain inorganic elements and compounds compared to environmental samples of water, sediment, and sand.
Among the most striking data points are the following: elevated levels of metals such as arsenic, cadmium, mercury, and leadwhich turn out to be far higher than those recorded in the surrounding environmentIn addition, the presence of lufenuron in the fish's liver tissue, an insecticide used in veterinary medicine and agriculture that It does not appear in any of the open marine environment samples..
This difference in concentration points to a phenomenon of bioaccumulation of contaminants within fish farmed in cagesrather than diffuse contamination of the external marine ecosystem. The report emphasizes that the environmental samples were taken at a time with no indication of active chemical discharge, reinforcing the idea that there was no anomalous external source in the immediate environment.
In its technical conclusions, the document is unequivocal on one point: No analytical evidence was found to support the hypothesis of an acute toxic spill from the outside environment as the direct cause of the deaths.In other words, the chemistry of the water, sediments, and sand does not show an extraordinary pollution event that could, by itself, explain the mass death. de peces.
The report acknowledges, however, that Its scope is limited to toxicological and chemical analysisTherefore, it does not address biological, sanitary, or cage management causes. Even so, the objective data it presents They shift the focus to the interior of the aquaculture facilities, by placing the highest identified pollutant load in farmed fish.
An open investigation with more questions than answers
The combination of these elements—the Fisheries inspection that supports the good condition of the facilities, the company's complaint about a possible chemical spill, the labor complaint about biological risks, and the toxicological report that does not detect an acute episode in the environment— It creates a complex and, at times, contradictory scenario.
On one hand, the hypothesis of an external spill from an outfall The issue remains under consideration in the judicial sphere, given that it triggered the initial complaint and prompted the preventative closure of beaches. Furthermore, the absence of clear chemical evidence in the water and sediments This leads experts to look at internal factors within the cages, such as bioaccumulation, the health conditions of the fish, environmental stress, or possible failures in mortality management.
In parallel, the complaint for alleged breaches of occupational risk prevention regulations This introduces an additional front that could have significant administrative repercussions. The manner in which the dead fish were removed, the exposure of personnel to biological agents, the potential lack of training and protective equipment, and the absence of specific biosecurity plans are all aspects that the competent authorities will need to clarify.
All of this is happening while residents, beachgoers, and the tourism sector watch with concern the consequences of the crisis. The impact on confidence in the fish farms in Telde and the quality of the Melenara coastline This is no small matter, and the case has become an example of the extent to which aquaculture, waste management, and marine environmental protection are intertwined.
With the Prosecutor's Office investigation still underway, the scientific reports on the table, and the parties involved defending their positions, mass death de peces The situation at the fish farms in Telde still lacks a single, definitive explanation.What is already emerging, however, is a scenario in which it will be necessary to thoroughly review both the sanitation infrastructure and possible discharges into the sea, as well as the internal protocols of the sea cages, the prevention of occupational risks and the health control systems of aquaculture in the area.
