Two shipwrecks off the Thiruvananthapuram coast, including one dating back to 1752, are now home to 212 species, including several recorded for the first time from Kerala, a University of Kerala-Ecomarine survey has found.
The year-long marine biodiversity survey along several rocky reefs and the shipwrecks off Shangumughom and Anchuthengu was carried out by the Marine Monitoring Lab (MML) of the Department of Aquatic Biology and Fisheries. The project is supported by Ecomarine, co-funded by the Erasmus Programme of the European Union.
The list of species includes spiny seahorse (Hippocampus histrix), which is listed as vulnerable by the International Union for Conservation of Nature (IUCN), squat lobster (Raymunida bellior), camel shrimp (Rhynchocinetes durbanensis), red-white cleaner shrimp (Urocaridella antonbruunii) and orange cup coral (Tubastraea coccinea). They are among the species that were recorded for the first time in Kerala.
Orange cup coral (Tubastraea coccinea) | Photo Credit: Special arrangement
Researchers found that the two shipwrecks - one that of a Greek ship that sank in 1968 off Shangumughom, and the other that of Wimmenum, an older Dutch ship which sank in 1752 off Anchuthengu - had transformed into rich ecosystems.
“A biodiversity comparison of the 212 macrofauna revealed higher biodiversity at the Anchuthengu site (184 species) compared to Shanghumughom (125 species),” A. Biju Kumar, department head, Aquatic Biology and Fisheries, said here on Wednesday.
The Anchuthengu shipwreck, 272 years old, has supported prolonged ecological succession, serving as a habitat for larger groupers and other breeding organisms.
The wreck of the Dutch ship Wimmenum at Anchuthengu. | Photo Credit: Special arrangement
Human divers and Remotely Operated Vehicles (ROVs) were used to survey the rocky reefs up to 100 metres depth and shipwrecks off Valiyathura and Anchuthengu, which lie at depths of 40 metres and 55 metres respectively. The Dutch ship had previously been documented by local fishermen and the Friends of Marine Life led by Robert Panipilla. However, the Greek ship was photo-documented for the first time through this project, Dr. Kumar said.
Kerala University is one of the four higher education partners in Asia to establish MMLs under the Ecomarine Project, K. S. Anil Kumar, University Registrar and Legal Entity Appointed Representative (LEAR) of the project, said.
Life forms typically associated with coral reefs were found thriving in these rocky reefs and shipwreck sites, according to the university. “The wrecks may have been caused by tragic accidents resulting in loss of lives back then. But today, life is thriving in them,” Kerala University Vice-Chancellor Mohanan Kunnummal said.
The wreck of the Greek ship off Shangumughom. | Photo Credit: Special arrangement
According to the research team, the wrecks also are hotspots for commercially-valuable fish such as groupers, carangids, and snappers, supporting artisanal fisheries and functioning as artificial reefs or fish aggregating stations. The team found that the absence of trawling in Thiruvananthapuram has preserved many rocky reefs in good condition. They have recommended conserving these highly-diverse regions as biodiversity hotspots, allowing traditional fishers to sustainably harvest resources or manage community reserves.
One problem the survey identified was the presence of ghost nets on the Anchuthengu shipwreck. Ghost nets - nets discarded or lost in the sea - are a threat to marine life.
On the occasion, the Vice-Chancellor also released a book Comprehensive Guide to Monitoring Marine Litter and Analysing Microplastics in Aquatic Ecosystems authored by Dr. Kumar and Suvarna S. Devi.
