Orcas are the most widely distributed mammals on the planet, occupying every ocean. However, these magnificent mammals are facing a myriad of threats, from prey depletion, disturbances from vessel traffic and, of course, chemical contaminants.

In an effort to better understand the troubling reality these apex predators face in relation to contaminants, a new study published in Environmental Science & Technology has examined how orcas’ toxic diets are impacting certain populations exposed to high levels of POPs (persistent organic pollutants).

Known as “forever chemicals,” POPs have a long-lasting nature that disrupts orca immune and hormonal systems, affecting their ability to reproduce and even causes to cancer. These chemicals, been mass-produced for industries like agriculture, have been shown to accumulate in living organisms and persist in environments. These chemicals build up through biomagnification, advancing up the food web and impacting dolphins and whales the most.

With a particular focus on orcas in the North Atlantic, the study looked at the potential impact of diet preferences on orca health and found that orcas who fed primarily on fish tended to have lower contaminant levels compared to those whose diets focused on marine mammals. This is because the chemicals bind to fats and increase in concentration as they move up the food web. Therefore, mammals with more fat may be experiencing a larger build-up of chemicals in their system.

In response to the study’s overall findings, researchers are suggesting urgent action is needed to protect North Atlantic orcas and their ecosystems. This includes steps for proper chemical disposal, targeted conservation efforts and preventing the release of potentially more harmful contaminants, among other suggestions.

There goes the neighbourhood 

Looks like climate change may favour southerners — at least when it comes to birds. A study looking at protected areas in Canada, has determined that the make-up of the bird communities inside and outside protected areas are beginning to resemble each other as a result of climate change. 

The University of Helsinki study, which looked at data on bird communities in Canada between 1997 and 2019, found that southern species are increasing abundance, while northern species are on the decline.

So while protected areas geared toward the conservation of northern species such as the Lapland longspur remain important, researchers noted that conservationists will likely face additional challenges to ensure that cold-dwelling bird species continue to thrive as the climate warms and the habitat within protected areas changes.

As the environment warms, bird counts found southern species such as the grass wren and the northern cardinal were moving north in search of a suitable climate. “This indicates that protected areas, in particular, are highly significant for the northern spread of southern species.

However, protected areas cannot entirely guarantee protection for declining northern species,” said researcher Leena Hintsanen in the Science Daily article reporting the study. 

Steady as she goes

It’s been a long, long time since there was last good news to report on North Atlantic right whales. But, according to updated data released by scientists in the North Atlantic Right Whale Consortium, the population of critically endangered North Atlantic right whales appears to have levelled off after a decade of harsh decline.

This years annual population estimate by the consortium for 2022 is 356, and the 2021 estimate has been recalculated to 365 due to the number of calves born that year. The early-to-mid 2010s saw population estimates reach close to 500 whales, with that number falling to 356 by 2020.

While this slowing down of the decline is positive news, the whales still face myriad dangers due to ship strikes and fishing gear entanglement. It’s estimated that 32 human-caused injuries to right whales occurred in 2023. 

However, there have been no North Atlantic right whale deaths in Canada since 2019. This suggests rules in place since 2019 that cause sightings to trigger strict fishery closures are making a difference. 

The first wave