CONCORD, N.H. — Bears are bolder, mosquitoes are multiplying and stream-dwelling fish are stressed. Beyond hurting crops and helping the tourism industry, New England’s hot, dry summer also is affecting the region’s wildlife.

All six New England states are experiencing at least moderate drought, according to the National Drought Mitigation Center, with severe patches in all but Vermont and pockets of extreme drought in Massachusetts and New Hampshire.

Low rainfall also means low stream flow levels across the region. The U.S. Geological Survey says all six states have areas exhibiting moderate hydrologic drought, with severe spots in Massachusetts and one extreme area in Maine.

Low and warm water stresses fish, such as trout and salmon, forcing them to seek out deeper pools or spring holes. On Friday, the Connecticut Department of Energy and Environmental Protection closed portions of the West Branch Farmington River and the Farmington River to fishing through Sept. 15 after several fish kills.

“This is the first time in memory that we have found it necessary to take action like this to protect our fisheries on these rivers, and it is not a step we are taking lightly,” said Deputy Commissioner Susan Whalen.

In Maine, officials are recommending that people fish earlier or later in the day when temperatures are cooler. The same goes for southern New Hampshire, said Scott Decker, inland fisheries program director at New Hampshire Fish and Game.

Given that mosquitoes breed in standing water, you might expect fewer instead of more during a drought, said Pete Pekins, wildlife professor at the University of New Hampshire. But the opposite happens because as water levels drop, river banks and the edges of ponds widen, he said.

Thanks to a mild winter and the current drought, water is warmer and more stagnant, which encourages growth of cyanobacteria, also known as blue-green algae, said Jeff Schloss, natural resources program leader at UNH Cooperative Extension. The resulting toxic blooms can hurt everything from microscopic organisms eaten by fish, to waterfowl that feed on those fish.

The drought has implications on land as well as water, with bears, snakes and ants among those species venturing farther afield in search of food or water. In Quincy, Massachusetts, a timber rattlesnake showed up on someone’s front steps. In New Hampshire, bears have been foraging for food at campgrounds and neighborhood trash cans because drought-stricken berry bushes didn’t produce as much as usual.