The theme of Heritage Week in B.C. is ‘Heritage Afloat,’ and a variety of activities are taking place this week in local communities to celebrate fishing, Captain Vancouver’s voyages, early settlers’ boat travel and more.
These are the traditional concepts of heritage. Yet we should also consider the natural heritage that has supported an unbroken chain of human life since the end of the last ice age.
The heritage of White Rock includes the salt waters of the Georgia Strait. Their ebb and flow creates the sandy beaches, eelgrass beds, marshes and sloughs, and shapes the islands of the Salish Sea.
Our heritage includes the Fraser River that brings life-giving freshwater to the lowlands and deposits sediments that build up the delta landscape. And it includes the networking tributaries of the Serpentine, Nicomekl and Little Campbell Rivers flowing through the heart of urban and farming communities.
Afloat in all these waters are microscopic, light-loving phytoplankton, literally ‘plant wanderers’, that drive the food chain as they drift the waters of the world. These tiny plants capture sunlight in ring-shaped molecules of green pigment called chlorophyll.
During photosynthesis, the conversion of light to chemical energy, stored as sugar, the world’s phytoplankton absorb carbon dioxide from the air and release half the earth’s oxygen.
What more essential organisms could there be?
Phytoplankton thrive in the presence of certain nutrients, such as nitrate, phosphate and iron. This is why a group from Haida Gwaii attempted, controversially, to increase phytoplankton by depositing iron into the ocean. With good conditions, plankton proliferate rapidly, spreading through the water; a large bloom can be visible from space. This attracts animal life, as herbivorous species eat the phytoplankton and are in turn preyed upon by carnivores.
In contrast, excessive nutrient enrichment from fertilizer spills, agricultural runoff, or poor water circulation, can cause harmful algal blooms and the death of marine life.
Eutrophication is a concern on Roberts Bank, where tidal movements have been affected by the port and ferry terminal causeways.
The rich ecosystem at the mouth of the Little Campbell River is reliant on a healthy watershed. The marine food web is complex. As organisms at the lowest end – phytoplankton – provide food for a host of slightly larger creatures, including zooplankton, like jellyfish, and crustaceans such as copepods and krill.
Krill, one of the smallest animals on earth, is eaten by blue whales, the largest.
White Rock is a maritime community. The lowly phytoplankton is the epitome of Heritage Afloat, as it drifts the planet’s waters, making life possible by changing sunlight into life’s breath and food.
Anne Murray, the author of two nature books, writes monthly for Peace Arch News – www.natureguidesbc.com