A string of heartbreaking events over the last few weeks has brought heightened attention to a struggling pod of orcas living in the waters off the Pacific Northwest.
It began on July 24, when a 20-year-old mother whale was spotted carrying the body of her dead calf, who had been born less than an hour earlier.
The grieving mother, known as J35 or Tahlequah, has been clinging to the baby ever since, even receiving help from her fellow pod members to keep its body afloat.
It’s been two weeks and Tahlequah has not let go, leaving many concerned about her physical and mental wellbeing.
And, in that same group, scientists are now rushing to the aid of a 3-year-old calf dubbed J50 who appears emaciated and may have a life-threatening infection.
The circumstances are extreme – but these are just snippets of the ever-growing problems faced by the orca population in the region.
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A string of heartbreaking events over the last few weeks has brought heightened attention to a struggling pod of orcas living in the waters off the Pacific Northwest. The grieving mother, known as Tahlequah, has been clinging to her baby’s body for two weeks (pictured on July 24)
WHAT ARE THE MAIN THREATS TO THESE KILLER WHALES?
According to the NOAA, the Southern Resident Killer Whales are up against three main threats:
- Lack of prey
- Boat traffic and noise
- Chemical contaminants
Chinook salmon are the most nutrient-rich prey available for Southern Resident killer whales.
But, the salmon’s population has plummeted in recent years, spelling disaster for the whales that rely on them.
Noise and overcrowding from boat traffic is considered to be one of the top threats to their existence, along with modern pollution and contaminants lingering in the water from chemicals banned decades ago
According to the NOAA, the main contaminants of concern are: PCBs (found in plastics, paints, rubber, electrical equipment), DDT (found in pesticides), and PBDEs (fire retardant chemicals found, for example, in mattresses, TVs, toasters).
Southern Resident killer whales, as the species is known, are one of the NOAA’s eight ‘species in the spotlight’ – or those considered to be ‘most at risk of extinction in the near future.’
The population now stands at just 75, which researchers say is the lowest number in three decades, made up of three distinct pods: the J-pod, the K-pod, and the L-pod.
All three groups have struggled to get their numbers up in recent years, data from the Center for Whale Research show.
The calf who died late July was the first to have been born in over three years.
According to the NOAA, there are three main factors threatening their survival: lack of prey, vessel traffic and noise, and chemical contaminants.
These whales can be found in the waters off Canada and the northwest United States, where the Chinook salmon population has plummeted.
And, as the fish are the whales’ main prey, the whales are suffering, too.
In addition to starvation, food scarcity has a number of consequences for the struggling species.
For one, scientists have found that it may be linked to the shockingly high miscarriage rates seen in this population.
Between 2007 and 2014, researchers found that as many as two-third of pregnancies failed, possibly due to stresses brought on by the lack of food.
Pictured, Southern Resident killer whale J50 and her mother, J16, swim off the west coast of Vancouver Island near Port Renfrew, B.C. J50 is the sick whale that a team of experts are hoping to save by giving her antibiotics or feeding her live salmon at sea
Chinook salmon are the most nutrient-rich prey available for Southern Resident killer whales.
In the study published last year, researchers from the University of Washington analyzed hormone levels from 348 scat samples.
This allowed them to differentiate between stress caused by external responses, such as boat traffic, and that resulting from poor nutrition.
And, they found food scarcity was a major player.
‘Based on our analysis of whale health and pregnancy over this seven-year period, we believe that a low abundance of salmon is the primary factor for low reproductive success among southern resident killer whales,’ lead author Sam Wasser, a UW professor of biology and director of the Center for Conservation Biology said at the time.
‘During years of low salmon abundance, we see hormonal signs that nutritional stress is setting in and more pregnancies fail, and this trend has become increasingly common in recent years.’
WHY DO SCIENTISTS THINK WHALES AND DOLPHINS MOURN?
Whales and dolphins have been spotted ‘carrying’ or caring for their dead young multiple times.
These creatures could be mourning or they have failed to accept or recognise that the offspring or companion has died.
Scientists still do not know if aquatic mammals truly recognise death and are looking to carry out more research on this issue.
In 2016, scientists found evidence that whales and dolphins hold ‘vigils’ for their dead.
They analysed several cases where mammals clung to the bodies of dead compatriots, and kept vigil over a dead companion.
At the time, they said the most likely explanation was mourning.
The study compiled observations from 14 events.
They found mothers often carried their dead young above the water, often flanked by friends.
In many cases, the dead offspring were decomposed, indicating they had been held for a long time.
Lack of food may even be causing the pods to behave in ways that are detrimental to their own survival, such as inbreeding.
As of this past spring, only 26 of the 76 whales were breeding, and a study identified at least four whales that were ‘highly inbred.’
It’s unclear what exactly is causing them to breed within their own families, but the experts say it may arise because families are staying close together to help each other hunt.
‘We found a hint of a relationship showing that the less diverse you are, the less likely you are to live long,’ lead author Michael Ford, a conservation biologist at NOAA Fisheries Northwest Fisheries Science Center in Seattle said in April.
‘We don’t yet know how much of a concern that is, but it’s something we want to look at more carefully. It’s possible that some of the problems this population has may be due to inbreeding.’
Scientists also identified worrying bacteria in exhaled breath from the killer whales’ blowholes that suggest they may be at risk of infections similar to diseases that affect humans and land-based animals.
The population now stands at just 75, which researchers say is the lowest number in three decades, made up of three distinct pods: the J-pod, the K-pod, and the L-pod. All three have struggled to get their numbers up, data from the Center for Whale Research show
The researchers from the University of British Columbia identified bacteria and fungi Salmonella, Staphylococcus aureus, Penicillium, and Phoma.
‘We’re not sure if these microbes naturally occur in the marine environment or if they may be terrestrially sourced,’ explained lead author Stephen Raverty, an adjunct professor at UBC’s Institute for the Oceans and Fisheries.
‘These animals are long ranging and as they migrate along the coast, they are exposed to agricultural runoff and urban discharge which may introduce a variety of microbes into the water.’
And, in addition to the environmental factors, the whales are facing increasing threats from human activity.
Noise and overcrowding from boat traffic is considered to be one of the top threats to their existence, along with modern pollution and contaminants lingering in the water from chemicals banned decades ago.
WHAT IS THE SOUTHERN RESIDENT KILLER WHALE AND WHY IS IT UNDER THREAT?
The Southern Resident killer whale is one of the National Oceanic and Atmospheric Administration (NOAA) Fisheries’ Species in the Spotlight.
This initiative is a concerted agency wide effort to spotlight and save the most highly at risk marine species.
The endangered Southern Resident is an icon of the Pacific Northwest but are also among the most contaminated marine mammals in the world.
The population census at the end of 2016 counted only 78 Southern Resident killer whales, down from 98 in 1995.
In 2003, NOAA Fisheries began a research and conservation program and the Southern Residents were listed as an endangered species in 2005.A recovery plan was completed in 2008.
The population continues to struggle and has declined over 10 per cent since 2005.
During the spring, summer, and fall, the range of Southern Resident killer whales includes the inland waterways of Washington State and the boundary waters between the United States and Canada.
They have been spotted as far south as central California during the winter months and as far north as Southeast Alaska.
Noise and overcrowding from boat traffic, as well as a scarce supply of their preferred food—salmon—pose serious threats to this endangered population.
Past research has shown that some of the most important threats facing the whales, such as prey limitation and high contaminant levels, cannot be addressed without a long-term commitment.
Recovery of threatened salmon, for example, is a monumental task in itself and is expected to take many years.
According to the NOAA, the main contaminants threatening these whales are: PCBs (found in plastics, paints, rubber, electrical equipment), DDT (found in pesticides), and PBDEs (fire retardant chemicals found, for example, in mattresses, TVs, toasters).
Conservationists are hard at work trying to protect the dwindling population in the waters off the US and Canada.
The NOAA has outlined a 5-year plan of action to aid in their recovery, and local governments have stepped up their efforts as well.
But, saving the Southern Residents will take a lot of work – and time is running out.
‘We are not too late,’ Barry Thom, West Coast regional administrator for NOAA Fisheries, said earlier this year.
‘From a biology perspective, there are still enough breeding animals, but we need to act soon.’