Tenerife sits in the eastern Atlantic like a crossroads. Positioned roughly 300 kilometres off the northwest coast of Africa, the island intersects the paths of the Canary Current, warm subtropical surface waters, and the deep cold upwellings of the Atlantic basin. The result is one of the most ecologically productive marine environments in the northern hemisphere, a place where bluefin tuna from the Mediterranean share waters with tropical reef species and migratory whales from the polar ocean. What lives in these waters, and how those populations are changing, tells us something important about the health of the broader Atlantic system.

The Anatomy of an Exceptional Marine Environment

The waters around Tenerife support approximately 400 species of fish, a number that reflects the unusual convergence of marine provinces that the island straddles. [1] Its seafloor topography is dramatic: the island drops away steeply from the coast, reaching oceanic depths within just a few kilometres of shore. This proximity of shallow coastal habitat to very deep water creates conditions that support both reef-associated species and the large pelagic predators of the open ocean, sometimes within sight of the same beach.

In the deeper offshore waters, the Canary Islands are internationally recognised as one of the finest big game fishing destinations in the world, and for good reason. Atlantic bluefin tuna (Thunnus thynnus) pass through in their thousands between December and April, migrating northward toward Mediterranean spawning grounds. These are not small fish. Individuals regularly exceed 250 kilograms, and the largest bluefin recorded in these waters approach 450 kilograms. [2] Their spring passage coincides with dense schools of Atlantic mackerel (Scomber scombrus) and smaller baitfish that concentrate near the island, drawing the giants in from the open Atlantic.

Blue marlin (Makaira nigricans) and white marlin (Kajikia albida) are present from spring through autumn, the two billfish species that define Tenerife’s reputation among dedicated sport anglers. Spearfish (Tetrapturus belone) inhabit the deeper offshore trenches. Yellowfin tuna (Thunnus albacares), bigeye tuna (Thunnus obesus), wahoo (Acanthocybium solandri), and mahi-mahi (Coryphaena hippurus) complete a pelagic assemblage that few locations outside the tropics can match. [2]

Closer to shore, the volcanic reef structures support a different community. Atlantic amberjack (Seriola dumerili), barracuda (Sphyraena viridensis), grouper (Epinephelus spp.), and European sea bass (Dicentrarchus labrax) inhabit the rocky substrates, alongside numerous wrasse species, bream, and moray eels. The deeper sandy bottoms, where slow-jigging techniques are most effective, hold species less visible to tourists but central to local gastronomy: red porgy (Pagrus pagrus), sargo (Diplodus sargus), and various sparids that have been fished by Canarian communities for centuries. [3]

Reading the Signals: What Is Changing

The richness of this marine environment is not static, and the signals coming from the water are mixed. On one hand, the resident cetacean populations tell a story of relative stability. Whale Watch Tenerife, which has logged cetacean sightings systematically since 2018, recorded 17 different species in both 2018 and 2023, with short-finned pilot whales (Globicephala macrorhynchus) and bottlenose dolphins (Tursiops truncatus) present on nearly every survey day. [4] In 2025, orca sightings and encounters with fin whales were notable additions to the year’s record. [4] The continued presence of these apex predators is generally a positive indicator of ecosystem function.

On the other hand, the EU-funded OCEAN CITIZEN restoration project documented concerning trends at the base of the food web when it began its work on the island in 2024. Fish populations associated with rocky reef habitats have declined significantly compared to historical baselines. Seagrass meadows (Cymodocea nodosa), which serve as nurseries for juvenile fish and feeding grounds for sea turtles, have retreated across multiple coastal areas due to sedimentation, pollution, and rising water temperatures. Rocky reefs have been degraded by a combination of physical disturbance and the effects of ocean acidification. [5] These are not peripheral problems. Reef habitats and seagrass meadows are foundational to the productivity that ultimately supports the entire marine food web, from the smallest reef fish to the bluefin tuna and the pilot whales that hunt above them.

The Atlantic regulatory framework governing commercial fishing has also evolved. EU fisheries ministers, meeting in December 2025, set 2026 catch limits with 81 percent of total allowable catches in the northeast Atlantic at maximum sustainable yield levels — an improvement on previous years, though the failure to agree a mackerel quota for 2026 due to disputes with non-EU countries was a notable setback. [6] For sport and recreational fishing around Tenerife, a growing culture of catch and release has taken hold among charter operators, particularly for bluefin tuna, billfish, and other large pelagic species. Most reputable charters now apply mandatory release for bluefin tuna, reflecting both changing regulation and a shift in the values of visiting anglers. [3]

What the Fish Are Actually Telling Us

Marine ecosystems are exceptionally good at communicating ecological stress, if we know how to listen. The presence of 28 cetacean species, including year-round resident pilot whales, tells us that the deep-water food web west of Tenerife remains productive. The decline of reef fish populations and seagrass cover tells us that the shallower coastal zone is under sustained pressure from human activity. The continued migration of bluefin tuna past the island tells us that large-scale Atlantic management is beginning to take effect after decades of overfishing. The appearance of orcas and large baleen whales in 2025 tells us that the waters retain the biological richness to attract ocean wanderers from across the hemisphere.

Tenerife’s marine environment is neither pristine nor beyond recovery. It occupies a contested middle ground where genuinely exceptional natural heritage coexists with the pressures of one of Europe’s busiest tourist destinations. Paying attention to what lives here, in all its scientific specificity, is the first step toward deciding what kind of relationship the island will have with its sea.

Sources

1. Wikipedia: Tenerife — fauna and marine ecology
2. FishingBooker: Tenerife Fishing — The Complete Guide for 2026, fishingbooker.com, January 2026
3. FishingBooker: Canary Islands Fishing — The Complete Guide for 2026, fishingbooker.com
4. Whale Watch Tenerife: Tenerife Whale Watching Season — cetacean sighting data 2023-2025, whalewatchtenerife.org
5. OceanCitizen EU: Reclaiming Tenerife’s Ocean, oceancitizen.eu, September 2024
6. European Commission Oceans and Fisheries: Fisheries ministers agree fishing opportunities for 2026, December 2025, oceans-and-fisheries.ec.europa.eu

There are few places in Europe where you can watch a pod of short-finned pilot whales (Globicephala macrorhynchus) year-round from a small boat, barely twenty minutes from shore. Tenerife is one of them. The waters along the island’s southwestern coast host one of the most biodiverse marine corridors in the Atlantic, a stretch of deep, warm sea that has earned formal protection at both Spanish and European level — and a designation that no other place on the continent shares. Understanding what makes this ecosystem extraordinary is also, increasingly, a matter of understanding what threatens it.

A Marine Sanctuary Unlike Any Other in Europe

The Teno-Rasca Special Area of Conservation (ZEC Teno-Rasca) runs along roughly 80 kilometres of Tenerife’s western coastline, from the Teno Massif in the north to Punta Rasca in the south. It covers approximately 76,648 hectares of ocean, reaching depths of around 2,000 metres at its farthest southern point, and it forms the largest Special Area of Conservation in the Canary Islands within the European Natura 2000 network. [1]

What sets this stretch of water apart is geography. The island rises steeply from the ocean floor, and the deep underwater trenches close to shore create conditions that would normally only exist far out to sea: cold, nutrient-rich upwellings meeting warm surface waters, producing a dense food web that supports an exceptional concentration of marine life. Up to 28 species of cetaceans have been recorded here. [2] Most remarkable among them are the short-finned pilot whales, a resident population that does not migrate and can be reliably observed on almost any given day of the year, making Tenerife one of the very few places on Earth where this is possible. [3]

Alongside the pilot whales, bottlenose dolphins (Tursiops truncatus) maintain a permanent presence, while Atlantic spotted dolphins (Stenella frontalis), striped dolphins (Stenella coeruleoalba), and occasional transient species such as fin whales, sperm whales, and orcas are recorded seasonally. Loggerhead sea turtles (Caretta caretta) and green turtles (Chelonia mydas) inhabit the waters throughout the year, and hawksbill (Eretmochelys imbricata) and leatherback turtles (Dermochelys coriacea) are occasional visitors. [1]

Beneath the surface, the seabed is equally rich. The reserve contains sandbanks, rocky reefs, marine caves, and extensive meadows of seagrass known locally as sebadales — underwater prairies of Cymodocea nodosa that function as nurseries for juvenile fish, feeding grounds for sea turtles, and significant carbon sinks. These habitats are listed under the EU Habitats Directive as priority ecosystems requiring active conservation. [1]

In January 2021, the World Cetacean Alliance formally designated the Tenerife-La Gomera marine area as Europe’s first Whale Heritage Site, and the third in the world, recognising not only the ecological richness of the zone but also the island’s commitment to responsible marine tourism practices. [2] Mission Blue, the ocean conservation organisation founded by marine biologist Sylvia Earle, has also declared the area a Hope Spot in support of further protection efforts. [1]

Why the Coastal Crisis Threatens What the Reserve Protects

Recognition and legal protection do not automatically translate into good environmental outcomes, and the Teno-Rasca reserve exists within a broader coastal context that is under serious pressure. Tenerife welcomed 16.3 million visitors in 2025, and the strain that level of tourism places on the island’s infrastructure is becoming visible in its waters. [4]

The same coastline that contains Europe’s whale sanctuary also borders one of Spain’s most troubled wastewater management systems. Environmental NGO Ecologistas en Acción documented that approximately 57 million litres of wastewater are discharged into Canary Islands seas every single day, and the Court of Justice of the European Union formally condemned Spain in late 2025 for failing to adequately treat urban wastewater, identifying at least 12 critical locations on Tenerife alone. [5] While the worst contamination has been concentrated in the north and south of the island rather than in the heart of the marine reserve itself, discharges of this scale and consistency create cumulative effects across an interconnected ocean system. Microplastics, pharmaceutical residues, and nutrient pollution from sewage all move with currents, affecting the entire marine corridor.

The EU-funded OCEAN CITIZEN project, which selected Tenerife as its primary pilot site for marine restoration in 2024, has documented what decades of compounding pressures have already done: once-thriving fish populations have declined significantly, rocky reefs have been damaged, and seagrass meadows have retreated in several areas of the island due to a combination of pollution, overfishing, and rising ocean temperatures. [6] The project is working to address these losses through seagrass replanting, coral restoration including gorgonians and black coral populations, drone-based monitoring, and community engagement programmes designed to connect local residents to the conservation process.

There is also a contested infrastructure question. For several years, plans have existed to construct a new commercial port at Fonsalía, a location that sits within the Teno-Rasca conservation zone. Critics, including the international marine conservation organisation OceanCare, argue that the project was only made possible because the relevant coastal section was cut out of the protected area designation, not because it was less biodiverse. Local civic groups have organised in opposition under the name Plataforma Ciudadana Salvar Fonsalía. [7] The outcome of this dispute will have direct implications for the ecological integrity of Europe’s flagship whale sanctuary.

The Bigger Picture

Tenerife’s marine environment represents something genuinely irreplaceable in a European context. A resident population of pilot whales, 28 recorded cetacean species, seagrass meadows, deep-water reefs, and sea turtles, all within 12 nautical miles of a major tourist island, is a combination that exists nowhere else on the continent. The Teno-Rasca designation, the Whale Heritage Site status, and the OCEAN CITIZEN restoration programme all reflect a serious scientific and institutional recognition of what is at stake.

What is needed now is the political and economic will to match those designations with real infrastructure investment, consistent enforcement, and honest public communication about the health of these waters. The sea does not lie. And the pilot whales, whose ancestors have made this coastal channel their home for longer than any human record, are paying attention.

Sources

1. Teno-Rasca Marine Strip Special Area of Conservation overview, TenerifeDolphin.com and TenerifeWhaleWatching.com
2. AD Boat Rental: Tenerife — Europe’s First Whale Sanctuary, adboatrental.com
3. Whale Watch Tenerife, whale watching season data 2023-2025, whalewatchtenerife.org
4. Timeout: Tenerife Is Investing €81 Million Into A Massive Coastal Clean Up, timeout.com, March 2026
5. BritBrief: Health alert for Canary Islands — tourists warned about beach water pollution, britbrief.co.uk, January 2026
6. OceanCitizen EU: Reclaiming Tenerife’s Ocean, oceancitizen.eu, September 2024
7. OceanCare: Whales and Dolphins Off Tenerife in Danger, oceancare.org

There is more to see on a small island than just sun, sea and sand. I know I caught you with those ‘s’ words, but, alas, we now meet the ‘s’ word that so deters many of us. Science. There is so much science at play in small islands, qualitative and quantitative. As a young girl visiting the beach of my island home, I could see in short time-frames how my favourite place was changing. Shells swapped for plastic caps, wildlife disappearing and simply the taste of the sea water changing from what it was. I felt so helpless, seeing all this happening and not being able to do anything about it.

As I got older the talk of the time was ‘global warming’ and I came up with crazy, nonsensical ideas about refrigerating the perimeter of the ice caps, super condensing forests and even harnessing energy from active volcanoes… Well, maybe not all of the ideas were crazy but in the mind of a 10 year old in the 90’s from a country without internet at that time and leaders who prioritized oil and gas, they were. I also loved Mermaids, so the people around me didn’t take my imaginings seriously.

I learned by living. This is something very distant now, children have all the answers at the tip of their thumbs and only a scroll or keyword away. In my youth, my imagination brought me closer to understanding. As I got older still, I realized that learning is different for everyone, and education without entertainment is definitely less engaging.

Time flowed on, just like water, and I fulfilled the childhood dream of an academic career in the natural sciences with Marine Biology being a focus. I then diversified into the social sciences, finding myself enjoying the fusion of fields, realizing I had a knack for blending many different skillsets. It seems my imagination picked up these capacities and I had an epiphany. When I brought together my art, scientific academics and childhood dreams, I was able to create Mertrina, a mermaid character that bridges ocean literacy and fantasy.

I learned from the children I interacted with that the Ocean has grown into even more of an unknown, even more unreachable and unfathomable than when I was little, even when the coast is a few minutes drive away. We see the ocean every day as Islanders yet we are disconnected from it. We don’t even know how to swim. Our education system is focused on academia, and sometimes the day is so full we don’t get the time to even imagine. I thought about my own childhood and how meeting a mermaid talking about the ocean and how to protect it would have impacted me. Through different books with different writing styles and presentation of the same science, I felt I could reach every type of learner.

The reality of a grown woman creating something quirky is one not very accepted in many societies. No one sees the struggle as a graduate to find employment, the constant short term contracts and patriarchal workplace systems. There is a great deal of competition, as well as corruption, and archaic perceptions, that bar capable and competent women and dare I say mothers, from being adequately employed. I was always under qualified, over qualified or expecting, all barriers to securing a job apparently. In order to survive, desperation becomes the catalyst and from it anything is possible. Thus at age 30, Mertrina the Mini Marine Biologist Mermaid was brought into the world.

My hope is to bring wonder back, to connect everyone, not just children, to the water. Juggling everything is never easy, but I do hope to be able to find a balance that will allow me to attain at least a little stability in this unstable human world. We must reconnect with nature, understand where our ecosystem services are coming from and try to conserve our natural resources. I advocate widely for nature based solutions and the integration of local indigenous traditions and knowledge in these activities. Through poetry, visual art and storytelling, we can transform behaviours and change the trajectory of the decline we are seeing first hand.

Mertrina lives in the Caribbean Sea, but as we know all water is connected so we don’t know where she will visit one day! Sea you soon!

Written by: Katrina Khan-Roberts