The wildlife division of the state Department of Environmental Protection does excellent work on habitat conservation and protection of endangered and threatened species. We’ve recently praised it with regard to disappearing shore dune forests, federally threatened red knots and N.J. endangered beach nesters — black skimmers, piping plovers and least terns.
But that doesn’t mean that scientists can now replace nature and remake the “natural” world into what they think it should be or, worse, more to people’s liking. Intervening on behalf of some species and against others should be done reluctantly and with strong justification.
That doesn’t seem to be the case with state efforts to reduce the population of double-crested cormorants on a small island in the marshes behind Stone Harbor.
Some short trees and shrubs on Gull Island used to host nesting herons, egrets and ibises, like many others adjoining Jersey Shore estuaries where they feed. But in the last several years, the population has changed to cormorants, about 110 of them.
The state has responded to this shift in nature by destroying cormorant eggs. Its biologists said the droppings of the cormorants — despite guano being a precious fertilizer — is damaging plant life on the island in a way that the droppings from the other birds never did.
State officials have made no case that the preferred birds are threatened or endangered as a reason for their anti-cormorant campaign. Just that cormorants are in the ascendancy and, one other thing, they’re diving birds that sometimes interfere with fishing.
Given the absence of a compelling reason to fiddle with nature in this case, state officials should consider whether this few years of deviation from what they consider the norm might have causes that are temporary — or even involve other wildlife management interventions.
For starters, many “islands” in the marsh that host scrub trees were formed by people depositing dredged material from nearby waterways. Perhaps that’s the case with Gull Island. The DEP admits such material would help trees there now, but it has ruled out that formerly common practice.
The state hasn’t offered a reason why cormorants, which have shared habitat with herons and gulls for millions of years, are getting the upper hand now (if indeed they are). Maybe the renewed abundance of menhaden, a favorite cormorant food, has made the birds more common as well. Yet fisheries managers want to boost menhaden further, to super-abundance, to help increase the populations of desirable species such as striped bass, ospreys and eagles — which might increase cormorants well beyond the ability of officials to suppress their numbers. Such complications and unexpected effects are typical of messing with nature.
If the cormorants are indeed damaging the trees on Gull Island, presumably it won’t be long before they too abandon it as a nesting location. Then other species that nest directly on the marsh presumably would take over.
With people responsible for the actions that threaten 99 percent of the world’s species at risk, a better use of public effort would be to minimize and mitigate the destructive effects of humankind. A fundamental value of nature is that it isn’t planned and controlled by people. With so much of the world domesticated to human needs, leaving as much as possible to nature should always be the first consideration in wildlife intervention.