If you have been following Tomorrow magazine’s wildlife column, you will know by now that Portugal has an incredible variety of wildlife, including some species that most people do not expect to find here.
One of the most enigmatic of all sea creatures is the seahorse. These mystical creatures are usually associated with exotic destinations, bright blue waters, clear underwater visibility and coral reefs. Yet, they can also be found in Portugal. At least two different species live in our coastal waters and river estuaries. Very delicate beings, these little fish live in striking distance of major cities, fishing villages and busy ports where, fortunately for them, their existence remains reasonably unknown.
Named after the shape of their heads and snouts that resemble an equine, seahorses are part of the Syngnathidae family which also includes seadragons and pipefish. The Latin name hippocampus derives from the ancient Greek word composed of two terms: Hippos (horse) and Kampos (sea monster).
Commonly classed as a fish due to the presence of a swim bladder that provides buoyancy and also the fact that they use gills for breathing, these fish lack scales. Instead, they grow an exoskeleton. Their bodies are covered by bony plates covered with a thin skin. Seahorses are very slow-moving creatures that use their tails to cling to seagrass, rocks or any underwater structures preventing the ocean currents from washing them away. Without any teeth, they vacuum suck their prey, which consists mainly of microorganisms called plankton.
Perhaps the most astonishing fact about seahorses is that it is the male that gets pregnant and gives birth! That’s right, the female deposits the eggs into the male’s brood pouch on his abdomen and the male fertilises the eggs, becoming pregnant. The gestation period varies depending on the species, but once the baby seahorses are ready, the male expels them from his belly (gives birth!!).
Chameleons of the seas, seahorses are masters of camouflage, blending in perfectly with their underwater surroundings. Our Atlantic coastal waters are often turbulent and murky, making sightings very challenging. This, again, is an advantage for seahorses against natural predators and illegal catching. Much like the chameleons on land, seahorses have prehensile tails that can change colour to match the environment or express their moods, and they have the same ability to move their eyes independently.
One of the species found in Portugal is the long-snouted seahorse (Hippocampus guttulatus), also known as the spiny seahorse. With distinctive spines on the head, neck and back, these fish grow to 21 centimetres in length and live between five and seven years.
The other one is the short-snouted seahorse (Hippocampus hippocampus). As the name indicates, these animals have smaller head features and are smaller than their cousins, only growing to 15 centimetres in length. They are also more discrete in appearance without the obvious spines and live around five years.
Both species can be found in the east-Atlantic shoreline, from the UK to southern Morocco, including the Azores, Canaries and the Mediterranean Sea. However, there are not enough studies to confidently say that their territory isn’t larger than so far recorded.
Worldwide, around fifty species of seahorses roam our coastal waters and open seas. They are present in all continents with the exception of Antarctica and can be found in shallow waters of less than one metre deep but have also been observed at depths of one-hundred metres. The smallest relative is the Satomi’s pygmy seahorse (Hippocampus satomiae), a native to Indonesia and Borneo that only grows as much as 13 millimetres. The Shire horses of the ocean are the big-bellied or pot-belly seahorses (Hippocampus abdominalis) with adult specimens growing to as much as 35cm in length. These are found in the southwest Pacific around Australia and New Zealand.
ALGARVE – Ria Formosa Seahorses
In the Algarve, the presence of seahorses in the wetlands of Ria Formosa is reasonably well known locally, and several studies and conservation projects have taken place there over the last decades. Many of these projects are carried out by or with the local University of the Algarve (UALG). Projects here have included monitoring local populations, creating protected areas, improving habitat on selected areas and even breeding programmes in captivity with releases into carefully selected zones. Local tour operators offer seahorse observation programmes where they take small groups on a boat through the maze of Ria Formosa waters to snorkel and hopefully get a glimpse of these magical creatures. If you don’t fancy snorkelling, a visit to the Algarve Life Sciences Centre in Faro will allow you to see these seahorses in a very well-put-together exhibition.
LISBON – Tagus Seahorses
In 2019, a hotspot of seahorses was discovered in Trafaria, a small fishing port and village that sits on the southern side of the Tagus estuary just across from Lisbon. This finding propelled the creation of the Tagus Seahorses project in 2023 by the conservation organisation SeaTheFuture. This project aims to understand the actual dimension and distribution of both seahorse species found in the Tagus River and, by doing this, improve the global data-deficient record on these species. Project work entails regularly diving, counting and measuring individuals, collecting data on population health, range and main threats, and scouting for other hotspots along the estuary.
SeaTheFuture is also working with fishermen in Trafaria to promote the importance of protecting what the project sees as a flagship species for conservation worldwide (much like pandas or snow leopards).
Who knows, maybe we will see the development of seahorse observation programmes in the Tagus river in the future – an idea that will certainly bring opportunities to the local community.
seathefuture.eu/project/tagus-seahorses
