Stories from the Sea · Gulf of Maine

The Ocean Starts Upstream

Rob Moir argues that one of the most effective ways to help the Gulf of Maine is far inland, in the soils and forests that decide how fast rain reaches the sea.

By Dr. Rob Moir | Ocean River Institute

The Gulf of Maine is often described as a “sea within a sea.” Enclosed by Cape Cod, Nova Scotia, and Georges Bank, the Gulf forms a broad bowl containing three deep basins separated by underwater ridges and banks. Connected to the open Atlantic through a handful of deep channels, it is replenished by cold Atlantic water while receiving freshwater from more than 60 rivers.

Its watershed stretches from the St. John River, the largest river flowing into the Gulf, to small urban streams like Alewife Brook. Forests, farms, cities, and wetlands across New England and Atlantic Canada all drain toward this common sea.

This continual infusion of freshwater gives the Gulf a lower surface salinity, typically about 31 to 34.5 parts per thousand of salt, compared with roughly 35 to 36 parts per thousand of salt in the adjacent Atlantic Ocean. This results in a marine ecosystem well known for fish productivity.

The Gulf is more than an ocean basin. It is the downstream expression of everything that happens on the land that surrounds it. Every raindrop that falls within this vast watershed begins a journey toward the Gulf, carrying with it not only water but also sediment, nutrients, pollutants and heat.

Across the watershed, rain is falling on a different landscape than it did a century ago. Forests have given way to pavement. Fields have become parking lots. Roads have widened. Rooftops, sidewalks, and industrial parks now replace living soils that once absorbed rainfall. Fewer trees shade streams, while water that once seeped slowly into the ground now rushes across hard surfaces, carrying sediment, pollutants, and heat toward the sea.

Climate change is amplifying these changes. Massachusetts receives about the same annual rainfall it once did, but the atmosphere now holds more moisture and releases it in heavier downpours. Storms that once arrived every century are becoming familiar events, overwhelming streams and storm drains alike.

The Gulf of Maine inherited a patient watershed and is now burdened with an impatient one.

A patient watershed stores water. It cools it, filters it, and releases it gradually through springs, streams, and wetlands. An impatient watershed sheds water as quickly as possible. Every storm becomes a race to the sea, carrying with it soil, contaminants, and the accumulated heat of pavement and rooftops. Nature never intended rain to hurry.

We often speak of restoring oceans by working offshore. Yet one of the most powerful ways to restore coastal seas begins miles inland, where a raindrop first meets the ground.

More rain infiltrates where plants have rebuilt the soil. Through photosynthesis, plants turn carbon dioxide and water into sugars. Some of that carbon moves belowground through roots, root exudates, and decaying organic matter, feeding fungi, bacteria, and countless other soil organisms. Together they build the aggregates and organic matter that allow soils to absorb, filter, and retain water.

The long-running Jena Experiment in Germany demonstrates the importance of plant diversity belowground. Species-rich grassland plots supplied more recently fixed carbon to soil microorganisms, increased microbial activity, and accumulated more soil carbon than plots with fewer plant species. Diversity did more than fill the ground with additional vegetation. It supported a more active soil community and a greater capacity to build and retain organic matter.

Soil is something a living plant community continually creates.

In Japan, botanist Akira Miyawaki developed a method of restoring native forest communities by planting many locally adapted tree and shrub species close together. His method brings together species of different heights and from different stages of forest succession. The young plants soon occupy every level of the developing forest, while their varied roots explore different depths and associate with diverse communities of fungi and bacteria.

Mycorrhizal fungi extend fine filaments through the soil and form partnerships with plant roots. Plants provide the fungi with carbon produced through photosynthesis; fungi help plants acquire water and nutrients that roots alone may not readily reach. Some fungal networks connect more than one plant, creating possible pathways for the movement of nutrients and chemical signals. Belowground, the forest is not a collection of isolated roots but a living network of relationships.

Planting densely and diversely can accelerate canopy formation, root growth, organic-matter inputs, and the development of a forest microclimate. Leaves shade the ground. Roots open pathways for water. Fungi and microbes bind particles into porous soil aggregates. Fallen leaves and dead roots become new soil. With each season, the ground becomes better able to slow, absorb, filter, and cool the rain.

A patient watershed begins with a living soil.

As the forest matures, its own climate begins to change. A dense canopy slows the wind, shades the soil, and traps moisture close to the ground. Humidity rises, evaporation falls, and the forest floor remains cooler and damper. The living soil continues to deepen, storing more water while reducing drought stress and the risk of wildfire. The forest is no longer simply responding to climate; it is creating one.

Every decision we make about forests, farms, cities, and soils eventually reaches the sea. No matter where we live, we live within a watershed, and every watershed flows to an ocean.

We often imagine marine conservation beginning at the shoreline or offshore. In truth, it begins where a raindrop first meets the ground. Rebuild the soil. Restore the watershed’s patience. Give the Gulf a chance to heal.

To restore the Gulf of Maine, we must first restore the patience of its watershed.

The Jena Experiment findings are published in Lange et al., Plant diversity increases soil microbial activity and soil carbon storage, Nature Communications, 2015.

SEVENSEAS Media · Conservation Journalism for the Ocean