For man to act upon a call to save the ocean, and for the ocean to accept man’s offering – morphing it into a habitable home for its creatures – is a beautiful act of harmony between man and sea. Text by Tasneem Khan, Image by Tasneem Khan & Umeed Mistry

The ship is undoubtedly one of mankind’s engineering marvels – it represents innovation, application of physics, complex architecture, culture, history, trade, geographies, and migration. Every ship carries stories with it, and those that sink continue to gather stories and support lives long after their years of sailing. After traversing oceans and intimately knowing their character on the surface, these ships now witness the oceans’ depth and dynamics. Like everything that enters the ocean – they become a part of it, interact and react with it.

The ever-vital ocean yields an alchemic power – it conjures habitats and niches from what it is given. For centuries, humans have been tapping on this power by using sunken ships and other objects to create and enhance fish habitats in areas of low fish abundance or high fishing pressure. Quite like a rocky reef, these objects begin to house animals that require hard surfaces to attach to – tubeworms, oysters, scallops, snails and tunicates that weren’t able to live on the muddy seafloor now have a substrate that is critical to their existence.

A diver swimming through the bridge of the Thermopylae Sierra, found off Mt. Lavinia in Sri lanka

Shipwrecks are essentially new habitats with distinct communities living on and within them. The first organisms to arrive are usually algae and larvae. Over time, the wreck will tend to mimic adjacent and sometimes seemingly distant natural reef systems. This reveals an incredible amount of information about the movement and connectivity of plankton and genetic populations through the ocean currents. These submerged wrecks provide a snapshot into the evolution of reef systems, the movement of planktonic matter and the possibilities of artificial reefs.

If you have the opportunity to dive a recently submerged wreck and then visit it periodically afterwards, it is an eye-opening experience – observing the rapid colonisation by marine life and questioning how it simultaneously corrodes and preserves.

There are numerous examples of how wrecks make great artificial reefs and attractive dive sites, but they are also ideal in-situ laboratory and study sites. Marine biologists use wrecks and artificial reefs to investigate the effects of substrate complexity, observe changes that occur over time, and even for controlled species or community specific experiments. This furthers our understanding of the various ecological processes that occur in the ocean and on natural reefs, providing insight into how natural reefs may be able to recover from damage by natural or anthropogenic occurrences. Clues about adaptation, resilience, migration and mutation can teach us volumes about the origin of life, the future of our oceans, biomedical possibilities and survival in general.

The broken hull and cargo of the Thermopylae Sierra, now a thriving reef

In particular, sunken wooden ships provide a whole new world of exploration on marine invertebrates. All the wood that makes its way into the world’s oceans is also home to a staggering diversity of sea creatures. Research on the subject of ocean wood shows that these communities may even vary based on the species of wood itself.  Like termites, wood-boring clams are often the first to arrive. They feed on the dead wood and digest cellulose with the help of specialised bacteria. This frees up carbon energy from the wood in the form of clam excrement that other life forms feed on. These clams, while boring through and feeding on the wood, also create a maze of tunnels and holes in which other animals take shelter.

For the rest of this article and other stories from this issue, see Asian Diver 2017 Issue 4 No 148

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