Managing Shared Natural Spaces

 On small islands like ours, natural spaces are shared with wild flora and fauna. Dr Anjani Ganase discusses some human impacts that we all should be mindful of.

 

Human populations have expanded around the world, not only in cities and towns, but spreading into wilderness areas. It’s time that we learn to share urban spaces as well as to respect all natural spaces whether these are actively protected or not.

 

In Trinidad and Tobago, there is a surge in outdoor activities as people see the appeal of dancing/ working out/ being under the stars, with a picturesque backdrop of tropical forests, beaches and lagoons. Large group hikes (100+ persons) and outdoor fetes have become popular. On one occasion, I observed Pigeon Point beach in the days after a beach fete. Keep in mind that Pigeon Point occurs in Trinidad and Tobago’s only marine protected area with its unique habitat and biodiversity. Walking along the beach, I collected handfuls of cable ties, pieces of wires, beer bottle caps and cigarette butts that were pressed into the sand, even after organisers dutifully cleaned up. This is only the physical waste; the chemical waste would have washed into the lagoon and the sea. The sand along the stretch of the beach is compacted from the infrastructure, vehicles and foot traffic. Sand compaction makes it difficult for burrowing amphipods (crabs and small creatures), nesting turtles and other animals to utilise the sandy interface for digging, foraging and nesting. While the impacts do not sound severe, these slowly transition the beach away from being a home for coastal and marine life. Unfortunately, many activities like this are detrimental to the very environment we seek escape to.  We need to understand how these ecosystems work and how we impact the spaces we share with wildlife.

 

Beaches are home to many marine critters, seabirds and marine visitors. Photo of Pigeon Point Beach. Photo by Anjani Ganase

Physical impact

In responsible development of ecotourism products, it is important to understand the carrying capacity of a space. This refers to the acceptable number of visitors and activities in a location without doing harm to the environment and to avoid risk to the visitors themselves. Consider a hiking trail along the northern range, Rincon waterfall. Some steeper sections of the path require safety ropes; how many uses will that rope have before it snaps; how much foot traffic should be allowed before the path impedes on the forest connectivity? As infrastructure is installed to make it safe for us, how does this detract from the health of the ecosystem itself? It is a necessary balancing act.

 

More acute forms of disturbance are large events that bring an excessive number of persons into a sensitive ecological space. Hosting events such as fetes or outdoor activities often means adapting the space to the event - installation of stage, removal of vegetation, flattening of the ground, removal of supposed pests, obstruction of natural pathways. All these actions chip away at the health of the habitat and the organisms (big and small) that utilise the space - be it a beach or a forest, lake or lagoon.

 

Waste Pollution

Waste pollution is inevitable. Even if events or activities are carefully managed for waste, a portion of the waste will always be released into the environment however unintended. More persons present in a natural space correlates with more waste – chemical, biological, plastic - in the environment.

 

Remains of old boats along Pigeon Point facing the lagoon. Photo by Anjani Ganase

 

Light pollution

Artificial light at night has illuminated many coastlines, shores, and terrestrial areas around the world. Unfortunately, such light overrides the natural cycles of all creatures that use the night to forage, hunt, migrate. There are two main types of light pollution: pollution of astronomical light occurs where city lights (for instance) obscure the view of the starry sky; pollution of ecological light alters the natural light in a space be it terrestrial or aquatic impacting on natural activities. Light pollution can impact wildlife in several ways.

 

Unnatural light disorients navigating wildlife and have been associated with deaths of migratory birds from impact or flying off course because of illuminated structures along their flight path. For nesting marine turtles and hatchlings, artificial lights at night may resemble the moonlight and guide them away from the ocean. The exposure of bright lights to nocturnal creatures such as bats, birds, reptiles, and fish, can render some temporarily blind until they are able to adjust and alter behaviour. Some animals are attracted to the light, such as tarpon are often hunted in the beams of underwater torches of scuba divers at night on coral reefs. Bats/ frogs come to feed on insects attracted by streetlights. However, other animals, including many predators, avoid light which may reduce their foraging capacity, such as mountain lions.  Amphipods that forage along the beaches for marine debris or seaweed at night forage and feed less with greater light pollution.

 

At sea, zooplankton undergo vertical migration in the ocean water column based on light. At night, they would move towards the surface to feed on algae and then shift deeper to avoid predation during the day. As zooplankton is the basis for the ocean food web, obstructions to this food chain can have serious consequences. Artificial light limits both visual and audio communications. Glow worms flash to attract males. And during the new moon phase (dark nights) coyotes yip and howl to signal territory to rival packs.

 

Noise pollution

Noise pollution often occurs in conjunction with light and other pollutions associated with human activity. Certain moth species attracted to mercury vapour lights are vulnerable to predation as they lose the capability to detect predator bats because of the hums given off by the light.  Noise pollution in the ocean can be incredibly disorienting as sound travels more efficiently in water with behavioural and physiological impacts to marine organisms. Coral larvae are guided by reef sounds to encourage reef recruitment and are therefore impacted by industrial sounds. In noisy urban areas, hummingbirds seemed to increase their pollination activities; but the animals responsible for the dispersal of the seeds avoided noisy areas resulting in lower dispersal of seedlings.

 

Where possible, natural spaces should be protected to conserve function and biodiversity. In shared natural spaces, used by humans and wildlife - such as Pigeon Point Beach, or Tucker Valley in Chaguaramas - our activities must be suited to the environment and not the other way round. Think about where you walk, the noise you make and the waste you leave. As much as possible, the areas should not be fragmented by lights, pathways, waste or infrastructure even if temporary. Land-use planning in these areas is critical, to designate areas of minimal disturbance. More broadly, more must be done when it comes to land use planning and management at an island scale.  We must understand how critical forest reserves maintain watersheds, as well as the linkages to offshore and coastal spaces which harbour marine life important for our livelihoods.

 

References

Gaston, Kevin J., et al. "The ecological impacts of nighttime light pollution: a mechanistic appraisal." Biological reviews 88.4 (2013): 912-927.

 

Longcore, Travis, and Catherine Rich. "Ecological light pollution." Frontiers in Ecology and the Environment 2.4 (2004): 191-198.

 

Lynn, K. Devon, et al. "Artificial light at night alters the activity and feeding behaviour of sandy beach amphipods and pose a threat to their ecological role in Atlantic Canada." Science of The Total Environment 780 (2021): 146568.