Nigeria's mountain streams are a haven for special creatures—they need protection

Nigeria has many freshwater ecotourism attractions. Among them are the Ikogosi warm spring, the Osun-Osogbo river, and the Olumirin, Owu, Arinta and Ekor waterfalls.

Their scenic beauty and lush forests make these sites popular, but the impacts of human activities are likely to pose a growing threat to once-pristine freshwater systems.

The biodiversity and conservation value of these places has not been well researched. The conservation value of a freshwater ecosystem lies in its ability to support rare and threatened species, as well as species that indicate high ecological integrity. This is the ability of an ecosystem to support and maintain ecological processes and a diverse community of organisms.

To fill some of the gaps, my freshwater biodiversity research group collected samples of insects and other small creatures from four freshwater systems in the Obudu mountains, along the border of Nigeria and Cameroon. The area falls into the Lower Guinea Forest Biodiversity hotspot, where endemic and threatened species like western gorilla, red-eared monkey and drill gorilla are found.

There has been no previous study on the freshwater conservation value of the mountains, despite their known importance for biodiversity on land.

We also collected samples of invertebrate species from the Agbokim waterfalls and the Kwa river of the Cross River National Park, all along the Cameroon border.

Our findings revealed that the sites have very high conservation values. They have rare, notable and threatened invertebrates in the freshwater systems. These should be protected better.

Freshwater macroinvertebrates

Freshwater macroinvertebrates include aquatic insects like dragonflies, mayflies, caddisflies, stoneflies, bugs and beetles; mollusks like snails and mussels; crustaceans like crabs and shrimps; and annelids (segmented worms). Macroinvertebrates, particularly the stress-sensitive ones like mayfly, stonefly, and caddisfly, have been described as the best indicators of freshwater quality. Stress-sensitive insects are insects that decline in population when their environment is disturbed.

Understandably, conservation attention is often focused on larger animals like crocodiles, monkeys and gorillas. These are the flagship species often used to draw attention to a conservation area.

But the biodiversity and conservation value of the freshwater ecosystems are also important. Healthy freshwater systems are an essential requirement for animal and human life on land.

Freshwater macroinvertebrates are ecological engineers with several functions in freshwater ecosystems. They serve as food for fish in the water. The adult insects that emerge from the water are food for animals in the forests near the water.

Also, the presence of certain invertebrate species is a good indicator of good water and environmental quality.