Conservation for human well-being

Marine scientist, Dr Michelle Cazabon-Mannette, introduces the idea of conservation for human health and well-being, and suggests activities that the average citizen should engage in, to keep Tobago green and serene. First published in Tobago Newsday on Thursday, April 20, 2017

 Parrot fish have an important role in healthy coral reefs, grazing on algae, photo by Ryan P. Mannette

Previous articles in this column have touched on some of the ways we benefit from the environment. This week I’ll focus on the link between healthy marine ecosystems and human well-being, to illustrate why conservation is important. I’ll also talk about the keys to a successful conservation strategy, and what we can all do to help conserve the environment.

Healthy, functioning ecosystems perform a range of services that tend to go unnoticed, but upon which we heavily rely for all facets of our well-being including security, shelter, food and water, health, recreation and culture. These ecosystem services are divided into the categories of provisioning, regulating, cultural and supporting services. Healthy coral reefs for example, support the fisheries industry (provisioning), provide essential shoreline protection (supporting), play a vital role in the regulation of climate (regulating), and provide recreation and tourism opportunities (cultural). Therefore it is in our own best interest to work towards maintaining these services, and that is what conservation is about. More than simply trying to boost numbers of rare species, conservation is about promoting sustainable healthy functioning ecosystems so that we might continue enjoying their benefits.

Dr Michelle Cazabon-Mannette and a hawksbill turtle, subject of a study carried out in Tobago waters some years ago. Turtles have long been considered food by humans. Dwindling populations of turtles now require us to adopt conservation strategies to safeguard our marine ecosystems. Photo by Lee Ann Beddoe

This is no small task, and it requires that we first understand the components of the ecosystem and how they function together, and how our actions threaten the system.
There are broad scale threats such as climate change and plastic pollution that have negative impacts throughout the environment, and there are threats at a more limited scale that may directly impact only a few species. When we examine the role of each species however, we may come to understand how an impact seemingly limited to a single species may in fact have wider effects throughout the ecosystem. 

Each species in an ecosystem has a role to play in the food chain whether as producers of energy, consumers, predators or as prey to others. Some species are critical to nutrient cycling by transporting nutrients from one place to another, while others may contribute to the physical structure of an ecosystem and provide shelter for other species. Each species then contributes to the ecosystem structure and functions in a number of ways. In many cases there is a degree of redundancy, where multiple species perform a similar role, so that the loss of one may be compensated for by the presence of another. But in some cases, a species plays such a unique, critical role, that if its population is depleted or even lost, it can cause ripple effects throughout the ecosystem with major repercussions. Such species are called keystone species because of their unique roles and disproportionate effect on the ecosystem.

A hawksbill turtle glides over a reef in Tobago, where it feeds on the abundant sponge, photo by Ryan P. Mannette

Keystone species in marine ecosystems include: parrot fish (which are important reef herbivores grazing on algae which may smother coral); several shark species (which are top predators and act to control the prey population); large herbivores such as manatees and green turtles (which graze on seagrass beds and maintain their productivity); hawksbill turtles (which have a unique diet feeding primarily on sponge – a simple animal which competes with coral for space); reef-building hard corals (which contribute to structural complexity of the reef and provide shelter for a variety of smaller mobile species including fish, eels, crabs, lobsters); leatherback turtles (which feed primarily on jellyfish which don’t have many predators but which prey on fish larvae).

All sea turtles serve as important nutrient transporters, gaining nutrients in the habitats where they eat, and depositing a portion at beaches where they nest. These key species then, are often the subject of targeted conservation efforts when their numbers are observed to decline. There can be a tendency to focus on simply helping boost the population numbers, without a view to the broader ecosystem context. However, the aim should be restoring the population to levels at which they can fulfil their ecological roles, consistent with the broader goal of restoring functioning ecosystems to where we continue to benefit from their services.

With this goal in mind, the key principle behind effective conservation is reducing or eliminating the threats that are causing a decline in numbers in the first place. Programs that involve removing animals from the wild for the purpose of breeding for example, do nothing to address the threats that are causing decline in the first place, and may cause more harm than good by removing animals from the roles that they should be fulfilling; and therefore interfere with the functioning ecosystem. Conservation strategies therefore, should revolve around managing human behaviour to reduce our impacts, while reserving direct interference as a last resort when other management measures are not sufficient. Such measures include regulation of natural resource exploitation, minimizing our waste and generally regulating how, when and where we interact with the environment.  

Everyone can do their part towards conservation by making better informed choices. Here are a few ways to start:
•    Avoid single use plastics as far as possible. That means plastic bags, food containers, disposable plastic bottles, cups, straws and cutlery. Use re-usable products instead.
•    Never leave litter behind. Litter anywhere, no matter how small and even far away from the coast, will eventually wash down to the sea.
•    Stay informed and make informed decisions about what food you eat, products you use and activities you participate in.
•    Finally, help spread the word. Teach your family and friends, and speak up when you observe someone acting inappropriately. Help them to understand why it’s important and help them make better choices.



  1. FROM IAN LAMBIE: This is a well written article. My interest has been on the need to conserve through proper management of our marine food resources. not only our finned fish,but also our lobsters,conch,crabs, whelks etc.(There may be limited laws to govern the exploitation of our shrimp populations)
    Are you aware that our Fisheries Laws are more than 100 years old. Yes there have been amendments but the laws are obsolete and have not kept abreast of modern fishing methods and technologies.
    While most Caribbean Countries, including those on the Central American Mainland, have laws,which are vigorously enforced, to utilise their lobster and conch populations in a sustainable manner, Trinidad and Tobago have no laws aimed at conserving these marine resources. We do not have a Closed Season, a minimum size limit,a daily bag limit , Sanctuary or No Fishing Areas and other procedures to facilitate "sustained use " of these important food resources.
    Visit the internet for articles relative to the Conservation of Spiny Lobsters and Queen Conch in the Caribbean.
    With respect to exploitation of our shrimp populations, Gary Aboud of Fishermen and Friends of the Sea can assist.

    In Tobago : what about the decline in Flying Fish catches during the 2015 and 2016 Seasons ? No appropriate information published by the THA or the Fisheries Ministry. Is this a secret ?

    Then what about the level of pollution or the quality of the waters around Tobago. The THA was very annoyed with the Environment Tobago which published such information about 10 years ago. Seek information from the IMA, Pat Turpin and from Environment Tobago. They may advise that you not publish "unfavourable" information should you wish to maintain a good relationship with the THA.

    Do the villagers at Speyside and at Charlotteville still collect seabird nestlings from the St.Giles Islands "to make a cook" and is "Wildmeat" still being served at Village Harvest Festivals ...................during the Closed Season ???

    And what about a "True True" management Plan for the Buccoo Reef and Speyside Reef.(and other reefs in Tobago) The late Prof.Julian Kenny had been "fighting for this" for more than 50 years without success.

    I have written on the need to Conserve our Renewable Natural Resources including our Forest mammals, Birds and Fisheries, for many years. I am now retired so that it is up to younger and energetic folk to carry on the "fight" for the Conservation of our Environment and our Natural Resources , our wildlife (including fisheries) our land,our precious and limited water resources ,and our forests. (not in any order of priority. All are essential for a good quality of life) Best of Luck.
    Ian Lambie


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