Groton — Long Island Sound is home to “lots of very interesting beasts,” including 29 species of sponges, 183 mollusks, 327 crustaceans and 174 fish species, but there is no comprehensive set of maps showing the richest and rarest habitats planners could use to protect the creatures and their homes.

“We actually have kelp forests in Long Island Sound,” said Peter Auster, research professor emeritus at the University of Connecticut’s Avery Point campus and Mystic Aquarium, speaking during a panel discussion last week. “We need to look at the rare and vulnerable habitats and the unique distributions. We’d like to have ecological maps for the decision makers.”

Auster and two other panelists, retired state geologist Ralph Lewis and Roman Zajac, chairman of the Biology and Environmental Science Department at the University of New Haven, made the case for marine spatial planning for the Sound — a tool for guiding its future uses and ensuring current ones can continue — at a very timely moment.

The discussion took place on Tuesday evening at Avery Point. On Wednesday, the state House of Representatives unanimously passed the “Blue Plan” bill, which calls for creation of an inventory of resources and uses of the estuary. The bill, introduced by Gov. Dannel P. Malloy, is expected to be voted on in the state Senate next month.

“This is something that should have been done a long time ago,” said state Rep. James Albis, D-East Haven, co-chairman of the Environment Committee and a leading supporter of the bill.

He added that the Blue Plan, which would be created by the state Department of Energy and Environmental Protection and UConn, “is not an enforcement document,” but more of a roadmap for determining the best locations for energy cables or other infrastructure, as well as areas that should be avoided by projects because of the ecological sensitivity. Since much of the information has been compiled by federal, state and nonprofit agencies, the costs of compiling, organizing and collecting new data and maps will be limited, he said. The bill also enables creators of the Blue Plan to seek grants and donations.

House Speaker Brendan Sharkey, D-Hamden, also called the Blue Plan “long overdue.” It will be a complement to the port authority being created to market the state’s three deep water ports in New London, New Haven and Bridgeport, he said.

“Long Island Sound is an incredibly important natural resource for our state, both from an environmental perspective and as an economic driver,” he said. “The Blue Plan bill creates a comprehensive approach to preserving and utilizing the Sound as an asset.”

Nathan Frohling, director of Connecticut Coastal and Marine Initiatives for The Nature Conservancy, moderated the panel discussion at Avery Point, pointing out that proposals for the Sound such as the Broadwater Liquefied Natural Gas plant are likely to come up again. The project, proposed in 2008 and abandoned in 2012, drew considerable public opposition.

“What marine special planning is about is making wise choices about where human activities should occur,” Frohling said. “We know this is a very busy water body with many economic and cultural uses. But if a new use comes along, there is no planning in place to protect traditional uses like shellfishing and boating and the underwater habitats.

“We’re not talking about people not being able to go to their favorite fishing and boating areas,” he added. “But how do we make new uses compatible with existing uses?”

He and the panelists both noted that Massachusetts and Rhode Island have undertaken marine special planning for their state waters, and several European nations have also done it.

Lewis, also a professor in residence at UConn, said that while some geological and sediment mapping and sonar scans have been done, many of areas where the water depth is less than 20 feet remain a mystery.

“What we don’t know about are the shallow areas, and from zero to 20 feet is where most of the decisions take place,” he said. “We’ve done the basics, but where do we go from here?”

Those who undertake the Blue Plan project, he said, need to begin with a clear idea of the specific questions they want answered about the Sound to ensure that the right kinds of maps are created.

Zajac emphasized that a diverse collection of habitats can be found across the Sound, with different communities living in soft sediments, boulder fields and sandy, gravely areas. In the mud bottom areas alone, there is a large variety of worms, crustaceans, bivalves and other small creatures that are “critical food web components, all very, very essential to Long Island Sound fish.” The portion of the Sound east of the Connecticut River, he noted, has “very high species richness.”

A marine spatial planning project, he said, would distinguish the areas with the most versus the least species diversity.

All three panelists noted that there are large gaps in knowledge about the underwater lands and habitats of the Sound that need to be filled. They emphasized, however, that decision makers should not wait for perfect and complete collections of maps and data before they use what’s now known.

“We’re making decisions ad hoc now on really large projects as they come along that can create conflicts and socio-economic impacts,” Auster said.

j.benson@theday.com

Twitter: @BensonJudy