Sargasso Sea 

A Canopied Haven in the Open Ocean

Covering an area of the Atlantic ocean 1,100km wide and 3,200km long, the Sargasso Sea forms a unique underwater haven for a remarkable diversity of species. Bounded by four currents (on the west the Gulf Stream, on the north the North Atlantic Current, on the east the Canary Current, and on the south the North Atlantic Equatorial Current), which create a gyre, the Sargasso Sea is the only “sea” with no land boundary. The foundation of this remarkable ecosystem is the Sea’s own namesake — Sargassum — a golden drift algae that forms extensive networks stretching across the surface of the ocean. These networks of algae act like a forest canopy in the high seas, providing refuge, feeding grounds, spawning areas, and migration pathways for flora and fauna, both endemic and transitory.

If you dove into the clear blue waters of the Sargasso Sea, you’d find a plethora of species of all shapes and sizes. From seahorses, to marlin, tuna, sea turtles, and whales, species throughout the food chain rely on the unique Sargassum habitat. Notably, all European and American eels spawn in the Sargasso Sea, before slowly journeying to freshwater habitats on either side of the Atlantic. Many seabirds also forage in areas of high Sargassum density, relying on the wealth of food it provides. The Sargasso Sea supports a spectacular amount of biodiversity, which is important for the broader Atlantic ocean as well as coastal ecosystems along America and Europe. The biological, cultural, and economic value of the Sargasso Sea is immense, but it is at risk. 

Due to the circular nature of the currents, the Sargasso Sea collects a huge amount of waste — the North Atlantic garbage patch. The area is also threatened by shipping and its adverse effects: noise, pollution, and destruction of the Sargassum, as well as overfishing, and climate change. The Sargasso Sea is an immense anchor for the larger Atlantic ecosystem. Protecting this area benefits the many species who rely on the Sargasso Sea, as well as the cultural, economic, and biological human interests in the region. 

Lined Seahorse

Under the Sargassum

Lined seahorses live for only four years, and those four years are largely defined by a monogamous partnership that brings thousands of new seahorses into the world. Each morning, the pair re-establishes their bond through intimate dances. When ready to mate, the pair swims together, eventually embracing to complete the act. It is rare throughout the animal kingdom to find such stunning devotion. The name Under the Sargassum was chosen for the painting as a nod to the Sargassum seaweed canopy that provides the setting for this epic romance. The pair spends their lives dancing under the stars, sea, and Sargassum, and when the partnership is broken, the remaining seahorse almost always spends the rest of its life alone.

The lined seahorse is found across the Atlantic as far north as Canada and as far south as the Caribbean. The Sargasso Sea, which covers much of this home-range, is an important ecosystem for the lined seahorse. Although the species can be found at depths of seventy-three meters, with adults swimming freely through the water column, marine vegetation in deep and shallow water is critical habitat for the seahorse. Sargassum, seagrass, sponges, and mangroves all provide the seahorse with protection, surfaces to hold onto, and cover when feeding. Vegetation is also critical in the early stages of the lined seahorse’s life cycle, with juveniles staying close to the surface of the water amongst the Sargassum. The species moves from shallow waters to deep waters depending on the season, and are known to frequent oyster beds, banks with heavy vegetation cover, bays, and salt marshes. 

 

Reaching only 5.9 inches tall, and being weak swimmers, the lined seahorse must adapt to its surroundings in order to hunt and maneuver. They can be found in different colours, ranging from shades of grey and black to red, green, and orange. Each seahorse has a coronet near the back of their head which is unique to the individual, much like a human fingerprint. Although the species is sexually dimorphic, with males being larger in size with longer prehensile tails and a brood pouch, both male and females swim in an erect position using their small pectoral fins for guidance. Lined seahorses rely on physiological adaptations such as elongated snouts, independent eye movement, and camouflage to facilitate feeding. To feed, they ambush their prey and suck them into their snout. Lined seahorses feed predominantly on minute crustaceans, brine shrimp, mollusks, and zooplankton.

The lined seahorse is monogamous, forming life-long bonds between partners that are re-affirmed through intricate courtship dances every morning. Like with other seahorses, the male is the caregiver for their offspring. The male holds the fertilized eggs in his brood pouch for around 20 days. Over 600 eggs can be carried by a single male at a time. When ready, the male releases the live juveniles, which measure only 11mm, into the water column. Courtship between the male and female begins again almost immediately after the juveniles are released. The strength of the pair’s bond is such that if one mate dies, a new mate is rarely found. In such a short life, there is often only room for one relationship. 

IN PARTNERSHIP WITH

Prints Coming Soon

A special thank you to George Grall, a National Geographic photographer of over 30 years, who has spent his life sharing the wonders of the world through his photography. In 1995, while on assignment for Natgeo Magazine in Australia, George became the first person to photograph seahorses mating in the wild. His love of nature is clear in his artful, intimate photography, and it is an honour to include his imagery in this campaign.

The priority MPAs and their ambassador species:

Leatherback Sea Turtle

Thermal Dome

Lined Seahorse

Sargasso Sea

Juan Fernández Fur Seal

Salas y Gómez & Nazca Ridges

Laysan Albatross

Emperor Seamounts