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Here Comes the Sun(fish)

Bronx River Alliance

In early May, sunfish begin to create nests in the sand at the bottom of the Bronx river, carefully choosing gravel of all the same size to line the edges, in preparation for the warm weather and mating season. They are extremely sensitive to the health and conditions of their environment so their prevalence is a good indication for the river’s overall wellbeing. 

Last August, the Bronx River experienced a fish kill. An event leading to preemptive and unnatural fish death due to water conditions. Last summer’s event was caused by a surge of chemical waste from an unknown polluter causing water levels to rise, a putrid odor to be emitted from the water, and for fish to become so distressed that they were emerging out of the water to die. The river had been poisoned. This event led to the death of an estimated nearly 5,000 fish of all species, including sunfish, making their sighting this spring crucial in determining whether the river would be healthy enough for fish to return.
Fish, although not keystone species in the Bronx River, and indicative of the other river wildlife’s wellbeing. They are deeply entrenched in the food web, consuming species whose populations otherwise may grow out of control while being a prevalent food source for others. Without them the entire ecosystem could become less stable regardless of water quality, further increasing the stakes as to what environmental security could have been lost as a result of the dumping and subsequent fish kill.

The difficulty in addressing this kind of illegal dumping is that there is no way to determine on our own the kind of toxin that was emitted. Therefore we were unable to directly address the issue at hand and instead were forced to rely on hope. Hope that the water was moving quickly enough that no long term contamination would occur and that the water would soon be clean enough to continue to support the lives of the fish in the future. 

Although the fish are back this spring, their deaths are evidence of why we must continue to fight for the protection of the river. As the fight for preservation continues, it is devastating to see the progress we have worked hard to achieve being undone so quickly by a single and destructive release of toxic pollution. That issue is exactly what made the river desolate in the first place, and as we work to ensure the river will one day be fishable and swimmable, we need help keeping pollutants away from it. 

Advocating for change can be as easy as having conversations with friends and family about how to get involved in environmental conservation and stewardship opportunities, or talking to your local government about funding conservation projects and cracking down on illegal dumping. There is no wrong way to get involved. 

The sunfish are back, and hopefully soon in their full numbers. If you are lucky enough to see the gravel rings in the bottom of the river, remember how much it took to get there and join us in helping to keep them healthy.


by Isabella Romano|Ecology Assistant| isabella.romano@bronxriver.org


About the Bronx River Alliance

The Bronx River Alliance is a coordinated voice for the river that works in partnership to protect, improve and restore the Bronx River corridor so that it can be a healthy ecological, recreational, resource for the communities through which it flows.

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