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The Decline in Sea Turtles Negatively Impacts Ocean Ecosystems

Film director Marcus Altuve excelled in his movie, Eyes of the Earth, when he spoke with suspense about the Moroccan tortoise as one of the endangered species.

Indicating that determining the presence or absence of this species in the wild requires the cooperation of scientists with pastoralists, those who know the secrets of the Earth. The same approach necessitates itself towards sea turtles, as they face multiple human and natural pressures that have led to a decrease in their numbers. It requires concerted efforts of researchers with activists and parallel initiatives to highlight the role of sea turtles in preserving marine and terrestrial ecosystems. And their necessity for ocean biodiversity.

The founding of some fossils revealed a discovery, in Morocco, of remains of a turtle, which has a tubular nose that ends with a small, rounded mouth that opens forward, much like the head of a hippopotamus. The researchers confirmed that it was a giant tortoise found in the mud in a mining basin on the outskirts of Khouribga (a mining city), and it is believed to date back to the Cretaceous period, 67 million years ago.

In recent times, most Moroccan families used to, and still do, host wild turtles in their homes and pamper them, believing that they bring many benefits, while sea turtles suffer from various types of damage and deaths, bycatch, falling into nets, swallowing plastic waste in the sea and collisions with ships. Fortunately, Moroccans do not love their meat, and it is not consumed in Moroccan cuisine, and it has no place on the Moroccan table.

It is said that turtles helped many sailors, who discovered new lands, and to survive, but man turned out to be ungrateful, as turtles ended up on the International Union for Conservation of Nature’s Red List of Endangered Species.

Various researchers confirm that turtles have amazing navigational capabilities, as they accurately determine the place of their birth, and females return to the same beaches to nest. Even after so many years, they remember the place of their birth, supposedly guided by the Earth’s magnetic field. But there is another opinion that says that it is nothing but the use of a strong sense of smell.

Sea turtles play an important role in marine ecosystems and help maintain healthy coral reefs and seagrass meadows. They feed by digging and bottom carving, contribute to the recycling of important nutrients, and maintain the balance of bottom sediments. They also carry different types of plants and small animals on their shell, which in turn serves as an important refuge for different species and organisms.

It looks not handsome but meek and graceful as it navigates the seas with its streamlined body and oar-like flippers that help females dig nests; they also enable them to swim tirelessly, spend most of their lives in the water, only go to the beach to lay their eggs. Females must reach the shore to lay their eggs in the sand, at which point periodic migrations to and from the nesting beaches begin. Therefore, all sea turtles start their lives as hatchlings on the beach, and the males of those will not come out to dry land again.

During hatching season, young sea turtles emerge from the nests, rushing toward the ocean waters to survive. Few of them are caught on land or in the water, and whoever survives may have an average life expectancy of 80 years.

The land turtle is slow, but the sea turtle is fast. Its movement in the water can reach 35 kilometers per hour, especially the leatherback turtle. Adapted to life in the sea, it maintains strong ties with land at the same time.

Sea turtles are large reptiles with two lungs. Their large upper eyelids protect their eyes when foraging among coral reefs. They have no teeth, and their ears are not visible. They hear better at lower frequencies, and their sense of smell is strong. Males have a longer and stronger tails than females. And have longer claws on their front flippers, which help them hold on to the female’s shell when mating. They have a convex shell at the top, consisting of a bony base that helps protect them from their main predator, the shark, and avoid them from being hurt by coral reefs and sharp rocks. Each species of sea turtle has a diet, some of which are primarily carnivorous and feed on jellyfish, snails, crabs, shrimp, crustaceans, fish, mollusks, and other vegetarians that prefer seaweed and algae.

The reduction in the number of green sea turtles feeding on seagrass leads to an increase in vegetation cover, which in turn blocks the access of light to the seabed and accelerates the decomposition process leading to a growth in slime. The seabed, as a result, becomes crowded with algae, fungi, microorganisms, and invertebrates.

Mustapha Aksissou, professor at the Faculty of Science at Abdelmalek Essaadi University, confirmed that there are two types of sea turtles along the Mediterranean coast in Morocco, the loggerhead turtle (Caretta caretta) and the leatherback turtle (Dermochelys coriacea). The exploration of hatching sites and stranding spots along the Moroccan shores of the Mediterranean Sea and Atlantic Ocean started in 1999 with Dr. Manjula Tiwari in collaboration with the National Institute for Fisheries Research (INRH). And later in 2003 with Abdelmalek Essaadi University of Tetouan. Some reports that date back to the 1950s reported possible nesting sites for the loggerhead turtle (Caretta caretta) and the green turtle (Chelonia mydas) in southern Morocco. However, recent studies of the Moroccan coasts seem to indicate a significant decline and disappearance of nesting spots from these coasts. Carcasses and shells of turtles accidentally caught in nets or stranded on the beaches were found. Surveys have reported that fishermen regularly encounter sea turtles and often catch them in fishing nets, adds Professor Mustapha Aksissou.

Image2Professor Mustaphfa Aksissou conducts his research on the loggerhead sea turtle. (Image credit: Environmental Perspectives)

The digestive tract contents of a stranded loggerhead sea turtle (Caretta caretta) along the northwest coast of Morocco were analyzed. This is in order to understand the feeding areas or habitat of sea turtles and to avoid the impact of bycatch. The digestive contents of twenty dead loggerhead turtles in northwest Morocco were examined between 2002 and 2007. Prey weight showed a variation in diet; 41 species have been identified belonging to 8 families, dominated by fish, crustaceans, and mollusks. Waste of human origin has also been found in the contents of the digestive tract. Adult turtles feed largely on bottom prey, while young ones feed on marine prey in large quantities. So that class of 50 to 70 cm in size and shell length (semi-adults) consume 63% of the benthic prey and 37% of the marine prey. The variety of prey species consumed increases with the size of the turtles.

A specialized scientific team conducted research on a spatial scale, about 324 km, and a large temporal spanning about 24 years, from 1998 to 2022, on sea turtle chains in north-western Morocco. A total of 208 stranded turtles were recorded. Of these, 184 (88.47%) were loggerhead turtles (Caretta caretta), 21 (10.09%) were leatherback turtles (Dermochelys coriacea), and 3 (1.44%) were unknown.

The largest number of strandings occur in the summer and early spring, when the large trawlers, purse seines, and longlines are active near the Moroccan coast. The majority of loggerhead turtles measured were sub-adult individuals (81%), while leatherback turtles included sub-adults and adults. The data showed that Moroccan coastal waters provide important foraging habitat and/or migratory refuge for loggerhead and leatherback turtles, and bycatch and boat strikes in fisheries may be among the main threats to sea turtles in Moroccan waters. This study constituted an important baseline for the development of efforts to conserve sea turtles in the waters near the Moroccan coast of the Mediterranean Sea.

This study is the first long-term study of sea turtle populations along the northwest Moroccan coast. It provides useful information for the conservation of these reptiles in the Mediterranean Sea and the Atlantic Ocean. The results of the current study illustrate some aspects of sea turtle biology and the causes of their mortality in northwest Morocco. However, knowledge of sea turtles in Moroccan waters is still limited, and efforts must be intensified and focused on understanding their presence in foraging areas. Highlighting the need for additional studies to determine seasonal movements and habitats and characterize their numbers and demographic structure to facilitate conservation and management efforts.

Dr. Wafae Benhardouze, a specialist in marine biodiversity and secretary of the Association for the Protection of Sea Turtles in Morocco (ATOMM), said that before the year 2000, the studies on sea turtles were almost non-existent, as it was limited to some observations of the death of these creatures along some beaches of the Kingdom of Morocco. She suggested that measures to conserve these marine organisms necessitate first conducting scientific studies and research in various fields related to their life cycle.

Since 2002, she has conducted a study in preparation for a doctoral dissertation on turtles under the supervision of Professor Mustafa Aksissou. The study was considered the first of its kind and was part of a partnership project between the Faculty of Sciences of Tetouan and the National Oceanic and Atmospheric Administration (NOAA). It covered various coasts of the Kingdom along the Atlantic Ocean from Tangiers to Laayoune and in the Mediterranean Sea from the hotel to Nador, as well as the Strait of Gibraltar.

The study included a group of researchers on the problem of mortality, diet, genetic facto, and bycatch. The results of these studies proved the presence of three types of sea turtles: the loggerhead turtle (Caretta caretta) by 95%, the leatherback turtle (Dermochelys coriacea) by 4%, and the green turtle (Chelonia mydas) by 1%. It was also concluded that the diet of the species (Caretta caretta) consists mainly of mollusks, fish, and cnidarians, the most important of which is jellyfish. As for the diet of the species (Dermochelys coriacea), it depends mainly on jellyfish. The autopsy results also showed the presence of bags and plastic materials, as well as fishing remnants such as hooks and fishing net lines.

Depending on the results of the age group and genetic tests, it was found that the most prevalent age group found on Moroccan beaches is the young and semi-adult, which belongs to turtles that nest on the western shores of the Atlantic Ocean and the eastern shores of the Mediterranean Sea. Based on genetic analyses taken from samples of dead turtles caught by bycatch, it is accordingly assumed that the Moroccan beaches are a feeding place for sea turtles migrating from the western shores of the Atlantic Ocean and the eastern shores of the Mediterranean Sea.

In the context of studying the relationship of the massive spread of jellyfish along the northern beaches of the Kingdom of Morocco, especially in recent years, Dr. Wafae Benhardouze added that it was then assumed that pollution and climatic changes led to a change in the chemical and physical factors of the Mediterranean. And as it is a narrow and semi-closed sea, any change in physiochemical factors will have a faster and greater effect. Among the results of the change in these factors, is the increase in the fertilization rate of jellyfish. And since sea turtles are considered among the most important predators of jellyfish, especially in the northern beaches of the Kingdom, which are considered a place for feeding sea turtles, the decrease in their number due to pollution and bycatch has contributed significantly to the increase in the number of jellyfish on the northern beaches. Thus, the environmental impact has an economic effect in light of the decrease in the number of tourists coming to the north of the Kingdom, and socially among fishermen due to the poisoning of fish and fishing nets, in addition to devouring the eggs and larvae of fish.

Dr. Wafae Benhardouze recommended that scientific research should be encouraged and funded to protect sea turtles and all endangered marine creatures. Also, work to reduce pollution by organizing awareness campaigns and training courses, especially in coastal areas, and working to change the method and tools of fishing to become environmentally friendly and organizing continuous training courses for fishermen.

Image3Awareness workshop on the importance of sea turtles in the ecosystem and the role of fishermen in preserving them. (Image credit: Environmental Horizons)

Mr. Abd al-Salam al-Bakali, a fisherman from the city of M’diq, expressed his happiness in acquiring new knowledge about sea turtles that he did not know before. It was through training sessions that he and his colleagues benefited under the supervision of the Association for the Protection of Sea Turtles in Morocco. He appreciated the efforts of Professor Mustapha Aksissou and Dr. Wafae Benhardouze and the vital role they played in introducing the pioneering role of “Fakroun Alma”. “Fakroun” is the turtle name in the Moroccan dialect.

“We have come to respect this marine creature that provides us with a service without even knowing, helping us to combat the damage that is inflicted on us by the proliferation of jellyfish. We have also been trained on having the skills and techniques of removing the “Fakroun” from the nets, without harming it.” He added with a sigh, “We have become ashamed when we found that it has swallowed some plastic waste, but we will receive knowledge lessons in another training course soon, and this time with our children and wives.”

Turtle shells that used to be sold in the markets of northern Moroccan cities as parts for musical instruments are no longer found as they were in past decades. Thanks to the efforts of various activists and continuous awareness, this horrifying phenomenon ceased.

It is noteworthy that Morocco has become a magnet for the international community interested in preserving sea turtles and their environment. The city of Tetouan recently witnessed the largest conference to promote cooperation, exchange ideas, cross-pollinate perspectives, and share the latest knowledge about the biology of sea turtles and their conservation in the Mediterranean. It was organized by Abdelmalek Saadi University, Faculty of Sciences—Tetouan, and the Association for the Protection of Sea Turtles in Morocco (ATOMM).

It is also important to mention that the decline of sea turtles in the Mediterranean bank in Morocco requires the activation of various initiatives and recommendations issued by scientists, observers, and environmental activists, as well as follow-up and evaluation of previous strategies, such as the first global strategy established by the Sea Turtle Specialists Group (IUCN) in 1995 in the Mediterranean region. And those carried out by the United Nations Environment Program “Sea Turtle Action Plan” in 1999. The protection of sea turtles poses a challenge to scientists, researchers, the interested public, and the guardianship administration, as they will use during their life many natural environments in which they live, marine and terrestrial, transboundary, and international waters. This necessitates international cooperation from various countries on both sides of the Mediterranean, as well as other oceans; as they are migratory species, their path is affected by sea temperature as well as ocean currents. They return after decades to a specific area in order to lay their eggs, which requires the protection of nesting and reproduction beaches. It is not enough to preserve certain beaches over others beyond national borders.

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