How a Single Species of Fish Tells a Larger Story of Conservation at Lake Malawi

By Alex Dunn
March 3, 2019

It’s late November, the end of dry season, and the river is at its lowest mark, more a jumble of sticks and sand-covered rocks than a river.

I’m standing on the banks of the Bua River in central Malawi. 

Come December, the rains will start, the forests will green, and the maize will grow. Rainy season will excite the water cycle which begins by moisture rising from Lake Malawi, billowing into thunderous clouds, and hammering down onto the land. The rain will soak the wooded hills and farm fields and slick the mud roads and mire the wheels of bicycles and cars. Slowly the water will collect into tiny streams, gathering as it moves downhill, eventually emptying into this river and finally flowing back to Lake Malawi, only to do it all over again.

I’m at the river today to place thermometers, fancy thermometers, into the water. The tiny metal discs are part of an ecological monitoring project being conducted by my colleagues from the Malawi Department of Fisheries, the United States Forest Service, and African Parks. The thermometers will measure and record a year’s worth of temperature data, providing park staff with valuable information on the river’s ability to support the threatened, “mpasa” or “Lake Salmon.”

Bua River in Malawi
Bua River

The mpasa is neither salmon nor a fulltime lake species. It’s a drab fish that, like salmon, makes its way from Lake Malawi upstream in the rivers to lay its eggs—an evolutionary adaptation that is dependent on a healthy riparian habitat.

Mpasa, like so many global fish species, are declining due to human impact. A growing population around the park and lake means a growing demand for food, firewood, and agricultural land. Human necessity and ingenuity often push standard fishing and farming practice to the illegal. Living trees are cut down and turned into charcoal, and bed nets, distributed to curb malarial mosquitos, are used as fishing nets, their ultra-fine weave scooping every fish out of the water regardless of size and for the mpasa specifically it is the fish weirs constructed at the mouth of the river that limit the movement up or down stream.

Of the rivers that feed Lake Malawi, there is only one that flows through natural and protected land. The Bua River travels through the Nkhotakota Wildlife Reserve, a natural area consisting of 1800km2 and the biggest in Malawi. The reserve is operated by African Parks, my host and partner for a one-year Peace Corps Response position. The park encompasses rolling miombo forest, hills topped in afro-montane forest, and watershed for the Bua River. The forest, as it always has, serves to clean water and retain sediment, keeping rivers clean and healthy, and the presence of the plain m’pasa is sign that larger natural systems are operating correctly.

Many people don’t understand why scientists set out to conserve a single species, especially one as unassuming as the mpasa. E.O. Wilson uses the term, “biophilia,” or the inherent human love of our fellow species. This love often concentrates around “charismatic mega-fauna,” or those big, furry, lumbering creatures that get all the press, think lions, pandas, whales, and elephants. But, even tiny beetles, eyeless lizards, drab sparrows and plain fish like the mpasa are part of the biodiversity that is deserving of our affection.

Alex and his colleauges at Nkhotakota Wildlife Park
Alex and his colleagues at Nkhotakota Wildlife Reserve

People often ask, what will happen if we lose a tiny species like the mpasa? It’s difficult to fully quantify a specie’s role in the ecosystem, but with the loss of each species, the world loses a tiny piece of its genetic and natural diversity. Consider a food analogy.

If the baguette went extinct what would happen to Paris? Imagine the outcry, the mobilization. Baguettes are so emblematic of the place, so beloved, that they are the culinary mega fauna. But, what if New York lost the caraway seed, would there even be an outcry? Perhaps a select network of rye bread fanatics would take up arms but most of the world wouldn’t blink an eye. In this culinary analogy, losing something small like a single, flavorful seed from the culinary biosphere might not warrant updating a Facebook profile photo, but it would leave a permanent hole and raise the question, “would rye bread still be rye bread without the caraway seed? And the larger question, “would a Rueben sandwich still be a reuben sandwich without the rye bread?”

The thermometer has been secured to a rock, sunk under water, and its location marked with GPS. We make our way back to the truck and the road. As we walk we can see sign of elephants everywhere, cantaloupe sized balls of dung, cartoonish footprints as if made with a pie tin, trees as thick as my leg knocked over like matchsticks and stripped of their bark. Only a few kilometers from the beginning of the human world, the villages, schools, and highway the elephants have been visiting the Bua River and drinking from its pools. Our work brought us to the river for the tiny mpasa, but the same conservation work ripples out from the tiny to the enormous. In this reserve, in this forest, the work of African Parks to conserve and monitor its natural diversity is having positive effects. From one little known fish to Malawi’s “baguette,” the African Elephant, conservation in action is working.

Alex Dunn