Small but Critical / Our Invertebrates

This blog contains several references to invertebrates in northern Kenya’s Lake Turkana Basin, the arid terminus of Ethiopia’s Omo River and world’s largest desert lake. Within this “Cradle of Humankind,” species continually adapt, as explained in our NWNL Interview with Dino Martins, entomologist at Turkana Basin Institute.

Animal species in our watersheds quietly enhance and protect the health of our water resources. Yet, rarely do we give our fauna – from wolves to woodpeckers – enough credit. This is especially true of our smaller invertebrate species, which include butterflies, bees, beetles, spiders, worms, starfish, crabs and mollusks. Invertebrates span the globe in habitats ranging from streams, forests, prairies, and deserts to lakes, gardens and even glaciers. Sadly, these unsung heroes are often called “pests.”

Invertebrate atop Perito Moreno Glacier, Argentina

Invertebrates are defined by their lack of backbone, yet ironically, they are “the backbone” of our land- and water-based ecosystems. Comprising 95-97% of animal species, they keep our ecosystems healthy; and although spineless, they are a critical base of the food chains for many species, from fish to humans. Fly fishermen carefully study the macro-invertebrates in their streams and rivers before choosing lures of mayflies, worms and caddisflies that appear in different stages, in different seasons, on different streams.

Invertebrates benefit our world in numerous ways:

pollination – of fruit, grain, and native plants
seed dispersal – a job shared with birds
recycling of waste, nutrients and food for other species, including humans
production of nectar and honey as a healing resource and immunity booster
purification of water and the environment
creation of reefs by mollusks, especially oysters
being useful research specimens (Think of fruit flies in biology class…)

One of the most valuable contributions of invertebrates is the pollination of our orchards and fields by bees and bumblebees. Without this, human food sources would be quickly and greatly diminished. Bees also pollinate riverine vegetation needed to retain water and prevent erosion. It is as simple as “No bees – No vegetation – No water!”

Honey bee pollinating spring blooms in Raritan River Basin, NJ

Ancient and contemporary Mayans have known that invertebrates are the foundation of the living world. Thus mosaics of mosquitoes, still today in Guatemala, are the symbolic woven foundations of women’s huipiles (blouses). Worldwide, mosquitoes and macro invertebrates provide food for other invertebrates, notably juvenile fish – locally called “cradle fish” – in northern Kenya’s Lake Turkana gulfs and bays.

However, Lake Turkana fish populations have been greatly reduced recently due to overfishing and upstream Ethiopian dams. Fortunately, the Lake Turkana invertebrate bee population’s honey production has provided a needed alternative source of calories. Fewer fish, combined with drought-afflicted livestock and maize, have led the Turkana people to turn to bee-keeping as their new livelihood.

Honey production by CABESI a nonprofit in Kapenguria Kenya

Author Sue Stolberger describes another oft-overlooked role of invertebrates in her Tanzanian guidebook. She explains that many invertebrates are “expert at natural waste disposal. Beetle larvae dispose of leaf litter. Maggots, blowflies and others play a role in the disposal of carrion; and dung beetles dispose of excrement, which cleans up the excreta and fertilizes the soil.” [Stolberger, p 197.]

In tidal estuaries, purification of water by mollusks is much cheaper route to addressing pollution than governmental SuperFund Site cleanups. Oysters very effectively filter our rivers and bays. Today the New York-New Jersey Harbor & Estuary Program is reintroducing oysters into the Hudson and Raritan Bays to clean those waters and stabilize their shorelines and riverbanks. [See NWNL Blog on Oyster Restoration in Raritan Bay by NY-NJ Baykeeper]

A “living wall” of oyster shells in the South Atlantic

Few people are aware of the endurance and numbers of invertebrates. The dragonfly story is amazing. Known for accomplished gliding and crossing oceans, dragonflies form one of the world’s largest migrations. Due to their large numbers, they’re among the most ecologically important insects and are voracious consumers of mosquitoes, worms, crustaceans and even small fish. Kenyan entomologist Dino Martins explained to NWNL that dragonflies are also great bio-indicators of ecosystems’ health. The presence or absence of “different types of dragonflies and/or macroinvertebrates [that] tolerate different stream conditions and levels of pollution… indicates clean or polluted water.” [Utah State University]

Shimmering dragonflies and damselflies, butterflies and even snails have inspired beautiful art, poetry and other creative expressions. In Japan, generations of haiku authors have compressed the unique qualities of these special creatures into 17 concise syllables, as in this by Issa:

The night was hot… stripped to the waist the snail enjoyed the moonlight

—The Four Seasons: Japanese Haiku. NY: The Peter Pauper Press, 1958.

Even the descriptive names given to our butterflies evoke a sense of poetry: Pearl Crescent, Red Admiral, Question Mark, Mourning Cloak, Silver Spotted Skipper…. Seeing the opalescent Mother of Pearl Butterfly (Protogoniomorpha parhassus) and the electric Blue Pansy Butterfly (Junonia oenone oenone) in Kenyan forests could turn anyone into a lepidopterist and an artist.

Mother of Pearl Butterfly (Creative Commons)

Despite these valuable attributes, invertebrates are slapped at; often seen as bothersome and unwanted; and most dangerously, ignored in environmental policies and land use practices. Sadly, we now have many at-risk species: from bumble bees to tiger beetles and butterflies. Caddisflies that live solely in one stream are becoming extinct. To understand their role in stream ecosystems, talk to a fly-fisherman or visit a riverside tackle shop.

On land, herbicides are sprayed in fields and along our roadsides through the summer, killing large swaths of milkweed, the sole food of monarch butterflies. In Michoacan Mexico, the winter retreat for all monarchs east of the Mississippi, illegal deforestation now leaves tens of thousands of monarchs frozen to death annually. Their small pale carcasses silently pile up on the ground where there used to be dense oyamel pine forests protecting them from freezing temperatures.

When frozen, monarchs fall to the ground, folding their wings as they die

The biggest threat to invertebrates is the loss of native habitat to development and agriculture. Native bugs, butterflies, beetles and bees need native wildflowers. Flying insects in the US Midwest now lack the succession of wildflowers since midwestern prairies have been reduced to mere fragments, called “remnant prairies.” In 2013, entomologist Dino Martins told NWNL, “Farmers need to understand why leaving a little space for nature isn’t a luxury, but a necessity for productive, sustainable agriculture.”

The importance of wildflower habitat for invertebrates was publicized in the 1970’s by Lady Bird Johnson, wife of former President Lyndon Johnson, and actress Helen Hayes.. Now many municipalities, organizations and gardening groups are publicizing the importance of replanting native wildflowers (milkweed for monarchs!) and eliminating invasive species. Farmers, land managers, environmental regulatory agencies, park managers and home gardeners need to become more aware. They can help protect the soil and water quality of our rivers, streams, ponds, wetlands in many ways. Funding for that research is critical, as is promoting citizen-science training programs. We can all pitch in to weed out invasive species if we learn what to look for.

Signage identifying invasive species in British Columbia

Small critter stewardship is growing. There is good news. The use of “Integrated Pest Management” and reduction of pesticides and herbicides is spreading; awareness of the consequences of killing our invertebrates grows. Commercial and small farmers are learning to supply water in their fields for bees so they don’t waste energy looking for rivers. The Endangered Species Act supports the many organizations resisting the overuse of chemicals and unregulated land development.

NYC Butterfly Group uses citizen scientist to map NYC’s butterfly distribution.
Xerces Society for Invertebrate Conservation [www.xerces.org), begun in 1971 trains farmers and land managers to save forest, prairie, desert and river habitat for these invertebrates via newsletters, books, guidelines, fact sheets and identification guides.
National Wildflower Research Center,founded by Lady Bird Johnson in Texas, preserves N. American native plants and natural landscape
BuzzAboutBees.Net www.buzzaboutbees.net/why-are-invertebrates-important.html website offers in-depth facts and advice on bees and bumblebees, as well as books, advice on stings and best garden practices.

It is time for us all to identify and weed out invasive species; help monitor monarch migrations; support local land trusts preserving open space; and advocate for more wildflower preserves. Baba Dioum, a Senegalese ecologist wrote, “In the end, we will conserve only what we love. We will only love what we understand. We will understand only what we are taught.”

A caddisfly in the hand of a New Jersey fisherman

SOURCES

The Four Seasons: Japanese Haiku. NY: The Peter Pauper Press, 1958.

Stolberger, Sue. Ruaha National Park: An Intimate View: A field guide to the common trees, flowers and small creatures of central Tanzania. Iringa TZ: Jacana Media, 2012.

“What Are Aquatic Macroinvertebrates?” Utah State University Extension. www.extension.usu.edu/waterquality/learnaboutsurfacewater/propertiesofwater/aquaticmacros, accessed 4/30/18