The Decline of Southern Resident Whales

The last several decades yielded significant research regarding cetaceans. Much more is known about whales and dolphins than ever before. While humans are naturally awed by these mighty and majestic sea mammals simply by watching them, the recent discoveries relative to communication, intelligence, and migration make whales even more fascinating. Some of the inquiries, in fact, reveal promising results that can apply to humans and the environment. Yet whales do not adhere to human dictates, nor are they respected in every quarter. Thus, they find themselves endangered by human activity. No better example can be found than the Southern Resident Orcas.

About the Whale

Orcas, or Killer Whales, are more properly classified as dolphins rather than whales, possessing a long dorsal fin and distinct black/white coloring. The term “killer whale” was imposed on the species because of its propensity to attack other cetaceans. Orca attacks on humans are very few and far between. Females are sexually active after six years of age; once pregnant, they carry their young for a full 17 years before birthing.

Nursing under water, orcas provide very rich milk that fuels the rapid accumulation of blubber in the calf. The female may not bear another offspring until five to 10 years afterward. Orcas most often travel in pods—herds, for you landlubbers—that consist of up to 25 whales. They are found in every ocean but most often occupy colder waters where food sources are more plentiful. Among their preferred foods are:

  • Seabirds
  • Squid
  • Sea turtles
  • Sharks
  • Rays
  • Seals

Orcas are grouped into three categories: resident, transient, and offshore. Resident orcas differ from the other two categories in that their pigmentation and markings are more varied, and that the dorsal fin is more rounded at the tip. This group also diverges in the area of diet: resident whales are predominantly fish-eaters, requiring a narrower range of prey than transients or offshores. Southern Resident Orcas are the only resident killer whales to occupy the waters of the United States. While they are centered primarily off the coast of the Pacific Northwest, their migration patterns have placed their range between central California and southern Alaska.

The Habitat

In 2006, the U.S. National Oceanic and Atmospheric Administration (NOAA) designated part of that migration range as “critical habitat” for the conservation of Southern Resident whales. The criteria for this status are:

  • The endangered species must occupy the area.
  • The area must possess properties essential to species survival.
  • Those properties may require special attention and maintenance.
  • Adjacent areas are critical for survival and propagation.

The NOAA mapped out southern Alaska/Canada waters down to the Washington State/Oregon demarcation for critical habitat protections. This coastal region is home to several migratory species of fish, including salmon, sturgeon, and trout. These fish make their way from the ocean into freshwater rivers and streams for spawning. What happens there in turn affects the sea mammals that feed on them.

The Problem

Southern Residents feed primarily on Chinook salmon. Tragically, the rivers and streams swum by these fish have suffered a three-fold assault:

  • Over-fishing
  • Pollution
  • Damming

Chinook salmon, the largest Pacific salmon species, have been harvested extensively by commercial and sport fishermen. World demand for all kinds of seafood has skyrocketed, and Chinook is an international favorite—to the detriment of Southern Resident Orcas. Meanwhile, pollution poses yet another threat to these coastal waterways. Many contaminants can compromise the Chinook immune system, thereby threatening an already precarious population. Worse, the orcas—which store toxins in their blubber—can no longer metabolize these poisons safely if they do not get enough to eat.

These issues are further exacerbated by the diversion of water resources through dam construction and logging. Blocking reproductive migrations, trapping sediments, and destroying freshwater plant life are only three of several harmful consequences of damming the rivers. For example, the Snake River—running from Wyoming to Washington’s Columbia River—has seen a 90 percent drop in salmon populations due to the four dams erected over the years. Increased boat and vessel traffic off the coast has also contributed to killer whales’ decline.

The Solution

The oceans were never teeming with the Southern Resident variety. That acknowledged, they have dropped from a historic high of 200 to only 78 at last count. This is due in large part to the late twentieth-century practice of capturing them for entertainment shows at aquatic theme parks. Yet the more immediate threats are itemized above. Dealing with these constitutes the first step toward reversing killer whales’ decline in the Pacific Northwest. Pulling down the dams goes a long way toward restoring the salmon supply for the killer whales. Educating sportsmen and consumers about the ecological importance of the salmon can relieve some of the human pressures as well.

The Hope

There is value in preserving these largest of dolphins. They are at the top of the food chain; no other species preys upon them for sustenance, and they serve as a natural control for fish populations. Whale scat (excrement) is believed to offset carbon presence in the atmosphere by stimulating the growth of phytoplankton. Economically, these whales are a boon to the tourist industry. On the whole, they occupy the Earth and provide spiritual and emotional refreshment to all who witness them. Humans owe them much, especially survival.