Climate Change and Migration

By Colin Glover

Most of us are aware of the dangers and effects of climate change: rising sea levels leading to unprecedented land loss,  ocean acidification and the resulting decimation of coral reefs, severe and more frequent storms ravaging coastlines, and wildfires raging for what feels like forever.  However, there is one effect of climate change that I think does not get enough attention: migration induced or altered by climate change.

Many species depend on migration for essential resource and opportunities that are not available year round, or to find tolerable weather conditions during the summer and winter. Many species of birds for example, from Hummingbirds to Canadian Geese rely on migration to return to nesting grounds, or participate in an all you can eat buffet of some seasonal delicacy. To time these vacations, temperature can be an important signal to mark the time to begin the migration, especially for those species making long trips seasonally.  Thus, rising temperatures can confuse birds when it's time to begin the journey.  Sometimes this means missing out on an essential food source to replenish from the exhausting travel or to store energy for future use. It can also mean missed romantic opportunities to find a mate.  Other times it can be as simple as the birds aren't in the right physical condition to tolerate colder or warmer temperatures at their destination.  All these effects pose a serious threat to the viability of the migrating bird populations (Jay et al. 2017).

Canadian Geese in Flight
(http://images.fineartamerica.com/images-medium-large-5/canada-goose-migration-mircea-costina-photography.jpg)

This phenomenon is not limited to birds though.  Migration of fish and shellfish  populations can cause serious problems for fisherman.  For example, the Black Sea Bass population has migrated hundreds of miles north since 1990, found now in New Jersey.  Changes in fisheries extreme as this is a big challenge for both ecosystem management and fishing regulation. Some fisherman are now having to travel 10 hours north from where they used to fish, just to get to a small allocation of fishing waters since fish don't respect the arbitrary lines we use to delegate natural resources.  To combat this, instead of focusing of a single species,  regulation needs to be centered around a more holistic approach, that considers the aspects of the ecosystem, like ocean temperature and migration patterns, that support these important fisheries (Goode 2016) (Climate 2016).

Change in Distribution of Economically Important Fisheries (Climate 2016)

It may be difficult to imagine, but plants, despite their sedentary lifestyle, are not even safe from these effects.  Many plant species are moving north, and to higher elevations. In places, certain plants that do not migrate quickly enough face extinction.  This can hinder ecosystem services, such as carbon sequestration, which in turn can also contribute to the rapid rise in temperature.   This ecological disturbance can be beneficial to invasive species, which spread quickly and generally are less susceptible to the heat (Ronald et al. 2005).

It can be hard to imagine the communities we inhabit without iconic or economically valuable species. Fisherman and many more that rely on natural resources locally are at risk for financial hardship.  Not only is the land sinking into the sea, and forests lighting the sky in orange flame, but the animals and plants that make up many people's livelihood and love for the natural world are now leaving and in decline.  Foreign invaders are overtaking once familiar habitat for native species.  If serious steps aren't taken to reduce the anthropogenic element of climate change, the natural world around us may be very different, if not unrecognizable, from what we know today.

Works Cited:

“Climate Change Indicators: Marine Species Distribution.” EPA, Environmental Protection Agency, 19 Dec. 2016, www.epa.gov/climate-indicators/climate-change-indicators-marine-species-        distribution.

Goode, Erica. “Fish Seek Cooler Waters, Leaving Some Fishermen's Nets Empty.” The New York      Times, The New York Times, 30 Dec. 2016, www.nytimes.com/2016/12/30/science/fish-climate-        change-northeast.html?usp=sharing.

Jay, Zaifman, et al. "Shifts in Bird Migration Timing in North American Long-Distance and Short-    Distance Migrants Are Associated with Climate Change." International Journal of Zoology, Vol           2017 (2017), 2017.

RONALD P. NEILSON, author, et al. "Forecasting Regional to Global Plant Migration in Response  to Climate Change." Bioscience, no. 9, 2005, p. 749.