Tag Archives: Whales

Just keep swimming

This little critter is a limpet.  From the photo they may not look like the most exciting of creatures.  If you’ve ever been down to the coast and taken a look at them yourself… your opinion may not have changed.  They don’t seem to move around a lot, or do a lot.  Of course looks can be deceiving.  Under that shell is the limpet’s squishy body – and their big, muscular foot which, alongside a pretty amazing adhesive secretion, they use to cling onto rocks and other hard surfaces.  Anyone who has ever had a go at trying to get a limpet off a rock knows how good a grip they can have.  This fabulous foot isn’t just used to stop them from drying out when the tide leaves them exposed to the air, or keep pesky predators (or nosy humans) at bay.  Limpets are grazers, feeding on tiny algae on the surface of rocks with their raspy “tongue” (called a radula).  See that empty space behind the limpet in the photo?  That’s where it’s been grazing.  Once they have grazed an area they need to find more food.  That foot gets to work, and along moves the limpet, munching up all the algae in its path.  Some limpet species even appear to have a home – a particular crevice that they return to just before the tide will expose them to the air.

But this isn’t a post about how amazing limpets are.  This is a post about animal movements in the ocean.. Or at least 3 different types of animal movement.  Some of them move a lot further than you think.  Yes, even limpets.

Continue reading Just keep swimming

”Blue Whales have a subtle and not very convincing ability to get out of the way of oncoming ships”

Blue whales (Balaenoptera musculus) truly are the giants of the ocean.  Actually, they are the giants of the whole planet.  Reaching around 30 metres in length and more than 190 tonnes, they are the largest animal currently existing and, to the best of our knowledge, the heaviest animal that has ever existed.  Being so huge, risk of predation is low so they seem not to have really developed much of a threat-response system.  Of course that all changed with humans who became extremely capable predators, but on an evolutionary timeframe, that is an extremely recent event.  Hunting has largely ceased, but many endangered whale populations still face threats to their recovery and long-term persistence, threats like collisions with ships.  Research by Megan McKenna from the Marine Mammal Commission, alongside colleagues from Cascadia Research Collection, NOAA, and Stanford University​ reveals just why the blue whales are so vulnerable to ship strikes.

Continue reading ”Blue Whales have a subtle and not very convincing ability to get out of the way of oncoming ships”

Eavesdropping on an underwater world: Technology for Ocean Science

The ocean is not a quiet place.  Water can move rocks and sediment, even sufficiently to create underwater landslides.  Bivalves make clapping noises, fish make sounds during courtship, and cetaceans communicate with clicks and whistles, just to name a few.  And of course there is human activity – like shipping, drilling, and sonar, which all add to the sounds of the ocean.  There are many different reasons why we might want to hear these noises.  Thanks to acoustic monitoring technology we can.

There are many different types of acoustic monitoring equipment but you will tend to find one type of sensor at their heart – the hydrophone.  Hydrophones are microphones that can be dropped into the water and listens for sounds coming from any direction.  If you have been on a whale-watching boat you may very well have seen one of the crew drop one of these into the water.  With the hydrophone, the crew can hear a noisy whale and even work out their location.  In some places, hydrophones are anchored to the sea floor and float in the water column recording any sounds within their range, until their battery runs out and/or they are picked up again by boat.

Continue reading Eavesdropping on an underwater world: Technology for Ocean Science

Are we really protecting North Atlantic right whales?

With its common name originating from whalers who, because of their tendency to float on the surface once dead, decided that they were the ‘right whale’ hunt, the North Atlantic right whale (Eubalaena glacialis) has had a somewhat difficult past with people.  By 1530s Basque whalers where happily taking these whales (and others too) off Labrador and Newfoundland in the Northeast Atlantic.  By the mid-1600s, shore-based whaling took off down the east coast of the USA.  Between 1634 and 1951, it is estimated that somewhere between 5,500 and 11,000 right whales were killed by hunters.  1935 saw the introduction of the Convention for the Regulation of Whaling – the first protection afforded to these critters but many – but not all – whaling nations (Japan and the then Soviet Union being the exceptions).  Protection was bolsters in 1949 with the International Convention for the Regulation of Whaling (IWC), which banned signatories from hunting them for commercial purposes.  In the US, they were listed under the Endangered Species Conservation Act in 1970, and the subsequent Endangered Species Act of 1973.  Canada, who is not a signatory of the IWC, has listed them under their Species At Risk Act (SARA) as Endangered.  Today it is estimated that there are somewhere between 300 – 400 individuals left, and whilst commercial whaling has ceased, they are still under threat primarily from ship strikes or entanglement in shipping gear.

Continue reading Are we really protecting North Atlantic right whales?

Are we really protecting North Atlantic right whales?

With its common name originating from whalers who, because of their tendency to float on the surface once dead, decided that they were the ‘right whale’ hunt, the North Atlantic right whale (Eubalaena glacialis) has had a somewhat difficult past with people.  By 1530s Basque whalers where happily taking these whales (and others too) off Labrador and Newfoundland in the Northeast Atlantic.  By the mid-1600s, shore-based whaling took off down the east coast of the USA.  Between 1634 and 1951, it is estimated that somewhere between 5,500 and 11,000 right whales were killed by hunters.  1935 saw the introduction of the Convention for the Regulation of Whaling – the first protection afforded to these critters but many – but not all – whaling nations (Japan and the then Soviet Union being the exceptions).  Protection was bolsters in 1949 with the International Convention for the Regulation of Whaling (IWC), which banned signatories from hunting them for commercial purposes.  In the US, they were listed under the Endangered Species Conservation Act in 1970, and the subsequent Endangered Species Act of 1973.  Canada, who is not a signatory of the IWC, has listed them under their Species At Risk Act (SARA) as Endangered.  Today it is estimated that there are somewhere between 300 – 400 individuals left, and whilst commercial whaling has ceased, they are still under threat primarily from ship strikes or entanglement in shipping gear.

To help tackle the ship strike threat, Seasonal Management Areas (SMAs) were introduced off the east coast of America in 2008.  The rules are fairly straight forward, limiting speeds to under 10 knots (18.5 km/hour) for commercial vessels larger than 65 feet (20 meters) long.  There are currently 10 SMAs, which become active seasonally to capture when right whales are actually in the area, and then deactivate when the whales should have moved off.  Alongside the SMAs, Dynamic Management Areas (DMAs) were also brought it.  These zones are implemented when aggregations of the whales are detected in areas outside the SMAs.  For 15 days after detection, mariners are asked to avoid DMAs.  If they do pass through, they are asked to voluntarily reduce their speeds.  So do these zones work to reduce ship strikes on the right whales – and indeed any other large whale population that may find itself inside these zones?  According to this latest study lead by Julie van der Hoop from Woods Hole Oceanographic Institution… sort of.

Julie and her fellow researchers obtained confirmed mortality data for a whole host of whale species – not just right whales – that were reported along the American east coast between 1990 and 2012, alongside cause of death (if identified).  They also obtained sighting data from North Atlantic Right Whale Consortium database from 1990 to 2008.  This, the team report, will help them assess the whales’ occurrence inside – and indeed outside – the SMAs.  Some statistical, spatial, and temporal analysis later, and the team were able to tell us a little more about the effectiveness of these SMAs.

First to the mortalities.  Between 1990 and 2012, 1,198 confirmed mortalities were reported along the US east coast.  Most of the whales species were identified too – good news for the researchers, but cause of death was only confirmed with certainty in 458 cases.  In line with other study findings, entanglement was the leading cause of death, followed by vessel strikes.

The sightings data indicated that just 17% of the right whale sightings between 1990 and 2008 were outside the areas that would become SMAs.  In other words, when the SMAs were implemented in 2008, they were located in areas where 83% of sighting had previously occurred.  Not bad – its tricky to capture every individual in a management zone when those individuals tend to move around a lot.  So what of the strikes themselves… are they reduced?  Well the good news is that over the years right whale ship-strikes have shown a decline… though not directly coincident with the introductions of the SMAs (the decline started from 2007, the zones were implemented in 2008).  The researchers also note that active SMAs only encompass 36% of historical right whale strikes.  32% of the historical strikes occurred when the SMAs were active, but not in the areas the SMAs covered.

So whats going on here?  Well the team believe that the decline is right-whale strikes is likely down to a combination of measures introduced earlier – like voluntary and mandatory routing changes in the Bay of Fundy.  They also suggest that the SMAs themselves may not be as effective as they could be because of low vessel compliance (estimated to be around 21 – 33% between 2009 & 2011).  They also suggest that there is insufficient monitoring to detect just how effective these management areas are…meaning the management strategy could never adapt to be ‘better’ because no one knew that there was a potential issue.  The last major issue the researchers highlight is the timing and location of the SMAs.  The SMAs cover critical habitat and calving areas for the right whales but they are missing in the ‘migratory corridor’ that run along the east coast.  It is in this corridor where whales are most often sighted, and it in this corridor where strikes were frequent outside the active SMAs.  In essence, the SMAs are “spatially insufficient in certain seasons”.

Because the researchers only included records of animals found dead (either at sea or on shore) and not those found with serious injuries that most likely lead to death, actual mortality could be underestimated…and likely is – not all dead whales end up on shore, or float on the surface until spotted.  Which brings up another point.  Where the dead whales were spotted is not necessarily where they died (especially on shore).  The researchers recognise this, but note that drift data dead whales that were struck by ships is limited, and that drift would differ with location, making it difficult to determine where the whales actually died.

The paper which was published in Conservation Letters , and has been made open access.  You can have a read of it here http://dx.doi.org/10.1111/conl.12105

 

Image: North Atlantic Right Whale.  Credit Florida Fish and Wildlife Conservation Commission/Flickr (CC BY-NC-ND 2.0)

What the oceans do for us: Carbon Storage

We’ve all heard the news.  We have been – and continue to – pump too much carbon dioxide into the atmosphere.  Just like its ‘naturally produced’ counterpart, not all of the human-generated carbon dioxide stays in the atmosphere.  In particular, plants on the land are what we call a carbon sink.  They take up the carbon dioxide and use it for photosynthesis (which also produces oxygen as a waste product – hurrah for plants!).  Plants do a pretty nifty job but holding an estimated 85% of the active carbon on the planet and 25% of annual human carbon dioxide emissions, the oceans are also an extremely important carbon sink.

Continue reading What the oceans do for us: Carbon Storage

How not to hit a whale:  Move the shipping lane

Coming in at around 170 tonnes The blue whale (Balaenoptera musculus) is the heaviest animal known to have existed on Earth.  This huge critter feeds on some of the smallest, filtering zooplankton through its baleen plates that hang from its upper jaw.  The blue whale as a group (there are several sub-species) is unfortunately listed as Endangered on the IUCN Red List.  Commercial whaling certainly took its toll on the global population and was, without a doubt, the most threatening of human activities to these large enigmatic creatures.  With commercial whaling now largely ended, the human threat to their persistence has declined greatly.  But there are still incidents between humans and the blues, like entanglement in fishing gear and marine litter, noise pollution that can hamper their communication, and ship strikes.  Certainly the recovery of the blues in the eastern North Pacific isn’t as good as we would expect, but the reasons for this somewhat lacklustre comeback are much harder to pin down.  Many avenues need to be explored – including seemingly infrequent events like ship strikes.

Ladd Irvine of Oregon State University and a team of researchers wanted to take a closer look at blue whale movements off California, an area which also contains a great deal of shipping activity.  When looking at movement of any population, it’s really important to get as much historical data as possible because animals can vary their movements year on year.  The team used 15 years’ worth of data collected from 171 tagged whales.  These satellite monitored radio tags are pretty nifty pieces of kit, collecting the time and location of the whales at the surface and transmitting to satellites.  With this wealth of data, the team set to work figuring out which areas of the Californian coast are particularly important to blue whales.  Sure enough, some rather interesting patterns emerged.

Blue whales are attracted to the west coast of the US during the summer months to feast on the large numbers of krill found in the California Current System.  The krill are super-abundant during this time as a result of upwellings that increase productivity in the region, and by currents and the bathymetry (equivalent to topography – how the sea floor looks) of the area that concentrate the krill into certain areas.  As you might expect, the blue whales concentrated in areas where krill was most abundant.  Early in the summer the whales tended to stay in the more southerly sections, where upwelling intensity (and thus productivity) is fairly moderate.  During October and November the northern section of California experiences much stronger upwellings, and sure enough that’s exactly where the whales tended to hang out.  The whales don’t just head up north around the same time every year though.  Because the tracking data spanned 15 years, the researchers were able to compare movements over multiple years.  The timing of the more intense northerly upwelling varies year on year, and it was quite apparent that the whales tailored their northerly migration in line with this variation.  With variation in krill availability, you might expect that the whales would stay in California waters as long as krill abundance was high enough to give a decent meal.  Interestingly, the whales didn’t really alter when they continued on their migration out of California in line with productivity timings.  There was only one notable time when they did leave significantly later – in 2004.  What’s so special about 2004?  Well not much.  There was a weak  El Niño, but the researchers note that it didn’t really have an impact in the California Current System.  1999 was a super-productive year in the California Current System and no doubt prey was super-abundant.  Did the whales hang out there for longer than usual?  Nope!

So far so good, but the tracking data also revealed some potential issues.  The blues tended to be most concentrated alongside areas where human population is high, and where there are busy ports.  Busy ports means busy shipping lanes, which run straight through the places where the whales can be found.  Now remember that ship strikes are thought to be relatively infrequent, but the question is how do we know if there has been a ship strike?  Well first of all we have to know we have hit a whale.  Sounds daft, but if you’re in a huge freight vessel you might not notice.  You might also hit a whale and injure it (with unknown survival), or you might fatally hit a whale, and just not report it.  We do have evidence that on the whole ship strikes are on the increase, and this paper makes a seemingly simple suggestion to reduce the likelihood of a strike on a blue whale: move the shipping lane during the months when the whales are migrating through.  Of course such a move is an economic, political, and social minefield, but it’s not impossible – and there is a prescient.  Twelve years ago shipping lanes in the Bay of Fundy, Canada were moved just 6 km away from a key North Atlantic right whale feeding ground.  Since then, the right whale population has shown a small increase.  Of course correlation doesn’t imply causation, but it is food for thought.

This paper is published in the open access journal PLoS ONE.  Have a read of it here http://dx.doi.org/10.1371/journal.pone.0102959

Image:  Blue whales aren’t the only whale species to be susceptible to ship strikes.  This image shows an North Atlantic right whale (Eubalaena glacialis) who died after colliding with a vessel and suffering significant propeller cuts.  Credit: NOAA National Marine Sanctuaries/Center for Coastal Studies (Public Domain Licence)

Whale population shows signs of recovery… just in time for a new port development

The North Pacific population of humpback whale (Megaptera novaeangliae) has had its status under Canada’s Species At Risk Act (SARA) downgraded from “threatened” to “species of special concern” .

Sounds good doesn’t it!  Surely this means that the population is recovering from historical declines, and that the things that threaten it’s persistence are now under control.

….

Or maybe it means that now the whale’s status now in not quite as bad shape as before, it’s probably ok to stick a port to serve the $7.9-billion Northern Gateway pipeline off Kitimat in northern British Columbia, to ship diluted bitumen from.

I wonder which it could be.  Read the story as reported in the Vancouver Sun

Image:  A baby humpback breached several times near Tofino, British Columbia, Canada.  Credit Ethan Reitz/Flickr (CC BY-SA 2.0).

When ecotourism and whales collide

Ecotourism and nature-based tourism isn’t just gaining in popularity in some parts of the world – it has in some cases been heralded as a way in which we can help look after species that are struggling in the face of human activities that hamper their survival.  The reasoning behind this broadly falls into a couple of main camps.  First, by taking people like you and me out to see nature’s glory we may be more inclined to want to take care of it (“In the end we will conserve only what we love, love only what we understand, and understand only what we are taught.” ~ Baba Dioum).  Secondly, if we can give species some economic value through something like tourism, then taking care of them becomes important from an economic – and then political – point of view.  This sort of tourism isn’t without its controversy, with some activities having a larger environmental footprint than we may hope.  Even non-consumptive forms of eco and nature-based tourism – such as wildlife watching – can have a negative impact on the very species we are hoping to see and protect.

The waters around the Hawaiian Islands is a crucial area for humpback whales (Megaptera novaeangliae).  Roughly during December to April every year, thousands of humpback whales gather in these waters to breed.  So good are these waters, it is thought around 55% of the North Pacific population congregate in these waters to breed.  Some humpbacks even calve and nurse their young here.  This congregation isn’t just handy for the whales but also for people.  From a research, protection, and management perspective having a huge chunk of the North Pacific population entering one area every year makes life much easier for monitoring population levels.  And on that front we have some good news – humpbacks in the North Pacific seem to be on the up, with at least one study back in 2008 estimating around a 6% annual increase in population size (although the population still remained ‘Endangered’).  Research isn’t the only human activity to benefit from this congregation.  Humans have been interacting with whales since they first set out into the ocean.  Commercial whaling on an industrial scale has impacted on humpbacks over the last couple of centuries, reducing their population size to a small fraction of its pre-whaling size.  Commercial whaling has now largely subsided and in more recent decades we have switched from consumptive use of these whales to non-consumptive – whale watching.  Hawaii with its large congregation is a great place to spot whales – and a great place to set up a whale-watching business.  Whale watching seems a pretty benign activity right?  You go out, spot some whales, take some photos, perhaps listen to their calls if the boat is fitted with hydrophones, and if you have a good guide, you’ll get to learn something about these magnificent creatures.  Unfortunately, research by Marc Lammers of the University of Hawaii and colleagues has revealed that even these activities can cause harm to the humpbacks.

Marc and his team analysed reported boat strikes on the humpbacks in Hawaiian waters between 1975 and 2011.  Their work uncovered 68 reported collisions, 63% of which struck calves and juveniles.  These guys tend to spend much more time at the surface than adults so it isn’t that surprising that the most strikes would be on this group.  None of these reported strikes lead to immediate fatality, but it isn’t known how the collisions may affect the whales in the long-term.  We do know that strikes can eventually lead to death, as evidenced by one calf discovered dead with severe wounds consistent with propeller damage.  What was interesting is what sorts of vessels were involved in strikes.  Yup you guessed it – 61% of the collisions involved tour boats – that’s the whale watchers, divers, and snorkelers.  There is legislation in place that states boats should not be within 100 yards (~91.4 meters) of a whale, and it may be that most vessels are adhering to this.  Speed of vessel at the time of the collision was only reported in 57% of the collisions, but this data showed that the mean maximum speed at the time of collision was 12.33 knots.  These boats weren’t watching the whales – they were travelling to find the whales (or return to their port).  It is also interesting to note that not all strikes were reported as the boats hitting the whales.  20% of the reported collisions where of the whales hit the boat.  Yes it can happen – check this video out of a dramatic (and now famous) whale hitting a yacht in South Africa and a slightly less dramatic one in Hawaii.

We are pretty sure that whale numbers are on the up, and as bad it is to strike a whale 68 reported strikes over 36 years doesn’t appear to be impacting on the population growth.  Now these are only reported strikes.  It is likely that more than 68 whales were struck during this period but the strikes were never reported, and the authors note “The lack of incidents reported involving large ships is somewhat curious”.  However, that population trend is still going up.  Never the less, the team’s research hints at caution.  Reported strikes have increased in more recent years, with the data suggesting that this is more a function of increased small boat traffic rather than purely down to the increasing number of whales.  Hawaii has both a legislative and ethical responsibility to looking after these whales, and another piece of the research hints at a possible route that could be taken to reducing collision.  75% of reported collisions occur during February – March, and 63% of all reported collisions occurring in a region called Maui Nui.  Directed management of vessels during these peak times and in peak areas just might prevent the death of a young animal.

The paper is published in the journal Journal of Cetacean Research and Management .  The paper is open access but a bit of a faff to download to read.  Here’s what you need to do.  First go here and then scroll down the list of papers (or search) for 13_2p073_080Lammers.pdf.  It’s the second one from the bottom.  Hit download, which then takes you to another page where they want you to say why you want the paper.  It doesn’t matter what you write – fill it in, hit download on this page and the paper is yours.

If you want to read up a little more on humpbacks and the status of the Pacific population, head over to the IUCN Red List.

Image:  Humpback whale.  Credit Christopher Michel/Flickr  (CC BY 2.0)

Japanese whaling in Antarctica challenged by Australia

The final day of a 3 week hearing into Japanese whaling in Antarctica finally reached an end on Tuesday.  But don’t hold your breath for the outcome – the court may take 4 – 6 months to make a decision.

It’s been a heated debate.  Japan argues that sustainable whaling is a fundamental objective of the International Whaling Commission – the voluntary body in which all of this is being debated. And they might be right.  Here’s some snippets from the preamble of the convention the nations signed up to

“it is in the common interest to achieve the optimum level of whale stocks as rapidly as possible without causing widespread economic and nutritional distress”

“establish a system of international regulation for the whale fisheries to ensure proper and effective conservation and development of whale stocks”

“to provide for the proper conservation of whale stocks and thus make  possible the orderly development of the whaling industry”

Under the terms of the convention, scientific research is allowed, and this is exactly what Australia’s argument is based on.  Japan’s research, Australia claims is “a heap of body parts taken from a large number of dead whales”.   Japan’s response?  “This court is a court of law not a court of scientific truth”.

Whether Australia win or lose the outcome may be the same.  Japan have already indicated that they would leave the IWC if they cannot continue their whaling operations under the terms of the commission.  The larger question may be is it better to have Japan in the IWC or out.

Dr Tony Press of the University of Tasmania has provided an overview of the hearing

Image: An adult and sub-adult Minke whale are dragged aboard the Nisshin Maru, The wound that is visible on the calf’s side was reportedly caused by an explosive-packed harpoon.

Credit Australian Customs and Border Protection Service (CC-BY-SA-3.0)