The most important factors in getting an impressive outdoor photo are catching the right light and always keeping a camera handy, said Tim Stamps, head of Marine Corps Base Quantico’s Natural Resources Branch and a first- and second-place winner in last year’s Earth Day photo contest.

While last year’s contest ran for a month, Natural Resources and Environmental Affairs would like photo submissions to reflect the base in all seasons, and the contest is already open for entries.

This year’s theme is “watersheds.”

Most of the water on the base drains into the Potomac River, which empties into the Chesapeake Bay, explained Maj. Peter Baker, the deputy at NREA. “The Chesapeake Bay is a highly polluted body of water that is of great concern,” he said, noting that locations throughout the bay’s vast watershed, including Quantico, are part of the Chesapeake Bay Program, aimed at protecting and restoring the body of water. The watershed encompasses about 64,000 square miles and spans Virginia, West Virginia, the District of Columbia, Maryland, Delaware, Pennsylvania and New York.

One of the best waterways for spotting wildlife is lower Chopawamsic Creek, Stamps said. He noted that tundra swans will gather on the creek in late February, around the time wood ducks — the area’s most photogenic duck species — will begin looking for nesting sites along the Chopawamsic and other bodies of water. Ospreys will arrive in mid-March, and beavers, otters and blue herons can also be spotted in the Chopawamsic and other streams on the base.

“Bald eagles are abundant in the area right now,” Stamps said, adding that they can be seen building nests or engaging in courtship displays this time of year. Deer, turkeys and songbirds can also be spotted all around the base, with deer more visible in the evenings, around 5 p.m.

Wildlife, however, is only one of the contest categories. Others include scenic landscapes, natural gardens, insects and recreation. There is also a junior photographer category for ages 16 and younger. Everyone can submit up to three entries in each category.

Stamps said some colorful buds will break in mid-March, but most flowering plants won’t be in bloom until April. He also noted that snow and ice of late winter weather can create photo opportunities.

There are a number of ways to adhere to the “watersheds” theme. For example, in the insects category, Stamps said, aside from the obvious water beetles and water striders, a number of insects, including mayflies, damselflies and dragonflies, begin their lives as water nymphs.

Ultimately, he said, the connection doesn’t have to be so explicit.

“The Chopawamsic Creek watershed is about 22,000 acres,” Stamps said. “A watershed is a large, encompassing area and definitely can include all the terrestrial animals.”

He said the fact that most of the creek’s watershed is forested, rather than developed, is the reason its water is so clean.

Baker said the photo contest was conceived as a way to “encourage people to get out and enjoy some of the natural resources we have here, since we put so much time into maintaining them and making them available.”

In addition to hunting, fishing and shooting photos, outdoor recreation options on the base also include bike riding, horseback riding, running and walking along many miles of trails.

Before taking photos on base, contact the Public Affairs Office at 703-432-0311 for a letter of permission. Contest submissions must be received by April 7, 2014. All entries must be in digital format and can be submitted via email at earthdayphotocontest2014@gmail.com or via Twitter with the hashtag #MCBQPicContest.

The entries will be posted to Facebook for a period of two weeks, during which the public will decide the winners by liking, commenting on and sharing the photos. Winners will be announced on Earth Day, April 22.

The rules and more details can be found at go.usa.gov/BQyx.