“Whales and dolphins today face more threats than ever before, and these threats are diversifying and intensifying. Many are critically endangered.” Ocean Alliance


Why Are Whales Endangered?

While measures for coexistence with whales can be implemented, it is necessary for regulations to be adhered to especially for the benefit of endangered species nearing extinction. We cannot expect whales to enforce these rules for us. These issues are important because our legislation governs not just how whales live but also how well they live in the oceans. Humans need to come to terms with the need to restore whale populations and remain lawful for the benefit of humanity.

Legislation for the protection of whales from commercial uses began in 1934 with the protection of right whales by international treaty after the development of synthetic oil to replace whale oil as a lubricant was developed (Roman et al, 2013).

The Marine Mammal Protection Act became law in the United States in October of 1972 followed by legislation for the ecological restoration of all marine mammals with the Endangered Species Act in 1973 (Roman et al, 2013).

The Marine Mammal Protection Act has two fundamental objectives:

  1. to maintain marine mammal stocks at their optimum sustainable populations, and
  2. for these stocks to exist as functioning elements of their ecosystems (Roman et al, 2013).

While Canada recognizes watching marine mammals in their natural ocean environment can give Canadians a better appreciation for marine wildlife, this can also lead to a risk of disturbing or harming marine wildlife (Oceans Canada, 2018).

Therefore, Canada has updated its Marine Mammal Regulations with amendments under the Fisheries Act in 2018 to set out required minimum distances required for whale watching and approaching marine mammals and further identifies that disturbing a marine mammal includes:

  • feeding
  • swimming
  • interacting with it
  • moving it (or enticing/causing it to move)
  • separating a marine mammal from its group or going between it and a calf
  • trapping marine mammals between a vessel and the shore, or between boats
  • tagging or marking it (Oceans Canada, 2018).

Human-Whale Interactions

As reviewed in the History of Whales section, humans and whales have had a past shrouded in the mist of whales as goods being shared globally for human benefit. Whales have clearly not benefited from humans interacting with them. While we may blame others for threats to whales, threats are a global concern caused by each one of us.

Before the late Pleistocene and early Holocene ages our world was full of giants, not just in the oceans but in terrestrial ecosystems (Doughty et al, 2016).

However, many of these species became extinct and whale populations of present times are decreasing from 66% to 99% (Doughty et al, 2016).

It is suggested blue whales are reduced to 1% of their populations in the Southern Hemisphere from their historical numbers as a result of commercial whaling (Doughty et al, 2016).


Currently there are 18 cetacean species and subspecies on the critical endangered list and 17 cetacean species and subspecies on the endangered list (Zhu et al, 2019).

Marine mammals face a complex mix of threats, including:

  • illegal hunting of whales
  • climate change
  • habitat loss
  • whale watching getting too close to whales which can interfere, harass or harm them
  • boats getting too close and separating mothers and their calves
  • small whales captured for display purposes in aquaria and hotels
  • small whales used for food in some parts of the world (The Marine Mammal Centre, n.d.)
  • mineral, oil, and gas extraction destroying benthic patches for feeding
  • movement to new foraging areas (Harwood, 2001)
  • violations related to domestic and foreign bycatch from fisheries
  • illegal shootings
  • oil and gas operations
  • contaminant levels exceeding thresholds for healthy marine mammals
  • biotoxins
  • algae blooms
  • rise of disease
  • ship collisions
  • declines in prey species
  • noise
  • disturbance (Roman et al, 2013)
  • infectious disease
  • bycatch
  • live stranding
  • starvation
  • interspecific aggression
  • physical trauma
  • polychlorinated biphenyls (PCBs)
  • naval sonar and decompression sickness
  • brominated flame retardants
  • reasons not established (UK Cetacean Strandings Investigation Programme (CSIP), n.d.)
  • sewage and garbage from cruise ships (National Geographic Society, n.d.)
  • previous commercial whaling of tens of millions of whales
  • ship strikes/collisions
  • fishing gear entanglements
  • ocean noise
  • loss of prey base due to less whales to distribute nutrients in ocean waters
  • spread of disease
  • natural climate cycles with shifts in temperatures (Roman et al, 2014)
  • sewage
  • atmospheric deposition
  • agricultural runoff (Roman et al 2016)
  • destruction of habitat
  • invasive species
  • epidemics
  • wars and geopolitical transformations (Pschera et al, 2016)
  • strikes by ship propellers (Williams et al, 2016)
  • "intense competition among companies
  • over-capitalization
  • economic and political incentives
  • misleading concepts of maximum sustainable yield and lack of information about stock sizes
  • birth rates and ecological relationships” (Moss, 2017)
  • accidentally being captured in fishing gear
  • disruption by humans during whale feeding, nursing and resting periods (Fisheries & Oceans Canada, 2018)
  • research experiments including killing whales for studying (Markus et al, 2018)
  • availability of prey
  • increased noise levels from passing ships
  • vessel strikes
  • gear entanglement
  • pollution in the water (Oceans Canada, 2018)
  • human impacts, like industrial dumping, runoff, and leaching chemicals into the ocean
  • low-frequency active (LFA) sonar tests (Howard, 2019)
  • emissions (Svanberg et al, 2019)
  • debris ingested “such as plasticizers, chemical additives….absorbed persistent organic pollutants (POPs)…, and heavy metals” (Zhu et al, 2019)

Video Link: Release of Pilot Whale from Musquodoboit Harbour

Whale Maneuverability

Whales were once the largest creature in the oceans, but now they are diminished in size relative to human inventions. Humans have taken to the sea; however, we have forgotten to learn first how we can enter the marine ecosystem to create no harm to marine life.

According to Williams et al (2016), in addition to the above noted threats, in specific whale strikes, it is suggested relying on whales to avoid ships is unreasonable for a variety of reasons as whales are unable to:

  • determine a ship’s route due to an acoustic null that may be produced in front of a ship
  • they are less responsive when in surface activities
  • they have limited responses to ships
  • no horizontal movement
  • have slower vertical movement when not foraging until less than 1500 meters from ships
  • whales spend a majority of their time below the surface
  • single whale sightings are half as likely to be detected than a group of 2 to 3 whales at 1000 meters
  • only whales in surface activities are visible to ships compared to sightings of blow, dive, and fluke movements.

Further, a study specifically of blue whales, the largest whale that can reach 69-90 feet in length (What is the largest whale? A cetacea size comparison chart, 2018), noted the species are:

  • limited in their ability to adjust their response behavior
  • have relatively slow decent movement
  • no horizontal movement to avoid a ship (Svanberg, 2019).

While whales in large groups and in surface activities increases their detection, weather, such as heavy fog, substantially deceases detection (Williams et al., 2016).

Ship Maneuverability

The largest ship in the ocean can easily outsize a whale leaving them defenseless in their own home. While we cruise the surface of the oceans, we forget we are also cruising over living beings that are dodging surface intruders daily struggling for their survival. As ships increase in size, the survival chances of whales deceases.

Ships also have maneuverability issues operating on liquid surfaces with the largest ship being 1,188 feet in length (Scarpinato, 2016).

While the International Maritime Organization requires ships over 100 metric tons to have initial turning ability (“ITA”), an average cruise ship, for example, has an ITA of 405 m; however, 500 m ITA is required to avoid a whale strike by the ship’s propeller (Williams et al., 2016).

Ship Types

While we often think of ships as being those in our local communities, ships travel globally carrying goods to other global locations. Not only are there a variety of types of ships in the ocean but these ships vary in sizes and speed abilities.

There are many different ship types in the oceans such as:

  • merchant ships
  • tankers
  • passenger ships
  • speedboats
  • tugs
  • fishing boats
  • leisure boats
  • other types (AIS Marine traffic & Cruise ship tracker ⋆ Live Free ⋆ 2019, n.d.).

Technology, such as an Automatic Identification System (AIS) has been able to reduce blue whale strikes by 95% outside the coast of Sri Lanka by re-routing shipping lanes 15 mm southerly (Svanberg et al, 2019).

The use of AIS was able to suggest 82% of Roseway Basin, Scotian Shelf, Canada, would be an area to avoid, along with implementation of speed restrictions, for cruise ships as their patterns overlap with humpback whales (Svanberg et al, 2019).

Additional data used with mapping vessels included:

  • satellite transmitters on 15 whales
  • virtual movements of whales using historical and/or acoustic data
  • adding smaller fishing boat data without AIS tracking
  • whale behavior knowledge
  • charting speed restrictions and whale strikes
  • study of whale and ship density (Svanberg et al, 2019).

Speed Restrictions

Just as vehicles on land highways speed, ships speed in the oceans; however, whether speeding to deliver goods on time or getting to a destination early, life can be harmed in the process, such as marine life. There are speed restrictions in the oceans for conservation reasons to protect all whale species.

Outside of Panama AIS was used to determine separation between vessels and humpback whales along with speed restrictions to lower collisions (Svanberg et al, 2019). Unfortunately, it is suggested not all vessels comply with required speed restrictions (Svanberg et al, 2019).

In Canada speed restrictions are set for vessels over 13 m in areas of the Gulf of St. Lawrence at 10 knots in the presence of North Atlantic right whales and is voluntary outside restriction areas (Transport Canada, 2019).

Canadian ship speeding fines in 2019 included:

  • July 18, 2019: Canada fined one yacht $6,000 for noncompliance of speed restrictions (Transport Canada, 2019).
  • July 26, 2019: Canada fined a general cargo ship and a bulk carrier $7,800 for noncompliance of speed restrictions (Svanberg et al, 2019).
  • August 12, 2019: Canada fined 6 ships, ranging from $6,000 to $12,000, that were not in compliance with speed restrictions, including a container ship, general cargo ship, oil/chemical tanker, pleasure craft, and two rescue vessels (Canada, 2019).

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Created By
Maria Lisa Polegatto


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