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Swimming with Species – The Sei Whale
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Swimming with Species – The Sei Whale

Ever wonder how life is in the deep blue sea? What lives among coral reefs, undersea mountains and volcanos, grooves and caves? What the differences are between freshwater and saltwater biodiversity? What’s the biggest species? The fiercest? The weirdest? Well, we wondered too; and thus, let’s go Swimming with Species to find out all about animals that lurk in the waters around Canada!


Today’s species is the Sei Whale!

The Sei Whale gets its name from the Norwegian word, “seje” which means Pollack. It is fitting seeing as how the Sei whale is often found with the Pollack in Norway. The Sei whale is found all across the world both in subtropical, temperate and subpolar waters. They prefer mid-latitudes, and can be found in the Atlantic, Indian and Pacific Ocean. In the summertime they are often found off the Gulf of Maine and Georges Bank (between Cape Cod, MA, USA, and Cape Sable Island, NS, CA). At the water’s surface, sei whales can be identified by their long sleek body that is a dark bluish-gray to black colour and white or cream-coloured underside. They also can be sighted by their 10 to 13 feet bushy blow. If you spot a Sei whale, you might also see oval-shaped scars (likely from cookie-cutter sharks and lamprey bites). But it's unlikely that you will see one, because Sei whales are fast swimmers, reaching speeds over 55kmh, so it’s possible that by the time you realize it’s a Sei whale, it’s already swam away! Sei whales have a tall, hooked dorsal fin located about two-thirds down their back. Instead of teeth, Sei whales have between 219 to 410 baleen plates (long, finger-nail like plates) which are dark in colour. These teeth make it easy for them to feed on plankton (including copepods and krill), small schooling fish and cephalopods (including squid) which all consist of its preferred diet. They both gulp and skim their food, and dawn is when the Sei whale is most likely to be feeding. On average, Sei whales eat 2,000 pounds of food per day. In order to feed, Sei whales dive below the surface, and can dive anywhere from 5 to 20 minutes to feed. Unlike other whales, Sei whales do not arch their back before diving, they simply sink below the surface. [caption id="attachment_38577" align="aligncenter" width="960"] A photo of a sei whale mother with her calf[/caption]  Although it is unknown where Sei whales breed, it is known that they generally mate and give birth during the winter in the lower latitudes. The females breed every 2 to 3 years and have a gestation period of 11 to 13 months. When born, their calves are about 15 feet long and already weigh 1,500 pounds! The mothers will burse their calves for 6 to 9 months before weaning them off. Sei whales become sexually mature at 6 to 12 years of age when they reach about 45 feet in length. As adults, Sei whales can grow up 50 feet long and weight as much as 100,000 pounds, with the females slightly larger than the males! Their average lifespan is between 50-70 years. Although Sei whales are largely solitary animals, they have been known to swim in small groups, up to 6 at a time and on rare occasions up to 50 during certain feeding periods. The Sei whale is known for creating low-pitched sounds for communication. The Sei whales are under various threats. The three largest threats are vessel strikes, entanglement and ocean noise. Unintentional vessel strikes can seriously injure or kill Sei whales. With increased sea traffic in shipping routes, the unintentional vessel strikes increase, and so does the ambient noise and pollution. Also, getting caught in the fishing gear is another large problem. Getting tangled in the pots, nets, and traps can result in swimming long distances with gears or nets attached, which causes fatigue. Fatigue can then compromise their feeding ability and/or injure them severely. Severe injury can lead to reduced reproductive success and death. As for ocean noise, since the Sei whale communicates with low pitched sounds, so, the underwater noise threatens their ability to communicate. It can also cause erratic behaviour and drive the Sei whales away from their feeding grounds.

Swimming with Species – The Porbeagle Shark!
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Swimming with Species – The Porbeagle Shark!

Ever wonder how life is in the deep blue sea? What lives among coral reefs, undersea mountains and volcanos, grooves and caves? What the differences are between freshwater and saltwater biodiversity? What’s the biggest species? The fiercest? The weirdest? Well, we wondered too; and thus, let’s go Swimming with Species to find out all about animals that lurk in the waters around Canada!


Today’s species is the Porbeagle Shark!

The Porbeagle shark is found in open seas in the Northern and Southern Hemisphere. In the North Atlantic, if you are anywhere from Newfoundland to New Jersey to Greenland and Russia, you might have the opportunity to witness one. But do not fear, the Porbeagle shark is known not to feed on other mammals, and is actually recognized for its playful behaviour!  The main diet of the Porbeagle shark consists of herring, lancetfish and mackerel. However, they do also dine on cod, redfish, haddock, squid and shellfish. Overall, their diet consists of pelagic (open sea) creatures. If you think you see a Porbeagle shark, look for its distinctive features. It has dark bluish-grey to bluish-black colouring on its back with white colour underneath. On its tail, it has a secondary keel underneath its longer primary keel. This shark has a stout head, with a pointed snout and large black eyes. Its teeth are small and smooth-edged narrow, with lateral cusps at the base of each tooth. But its most recognizable feature is the white spot at the base of the first dorsal fin. https://www.youtube.com/watch?v=EHmWe0Qj4w8 The Porbeagle shark joins the other species of sharks found in Canadian waters including the white shark, salmon shark, and shortfin mako. Different from other shark species', the Porbeagle shark has to keep moving in order to breathe. It also has a heat regulating mechanism that keeps its body temperature 3 to 8°C above the surrounding water temperature. This shark is limited to where it can go, and so, it spends most of its time in waters between 8 and 13°C. When not in the cooler waters, the mature female Porbeagle sharks migrate south to the seas between Cuba and Bermuda. It has also been seen near Brazil and Chile. It is in the warmer waters that the females pup, which occurs in late winter or early spring. Yet, their mating occurs in southern Newfoundland, in September to November. The Porbeagle shark prefers to remain in deep waters between 1,350 to 4,400 feet, but they often shift from shallow to deep, even being sighted in waters as shallow as 3.3 feet! The female can produce between 1-5 pups, but generally it is only four that are between 60-75cm long at birth. The female Porbeagles reach sexual maturity at a size of 217 cm long (which they reach around 13 years of age), while males mature at 174 cm (8 years old). The adults can reach a size of over 3 meters (10-12 feet)! Usually, it is only between 1.5-1.8 m and 135 kg (298 lbs). They have a life expectancy of 30-40 years, with most Porbeagle sharks indicating growth rings in the vertebrae that indicate at least 26 years of age before death. The biggest threat that the shark is facing is overfishing, both by fishing on purpose and by accident. This makes the Porbeagle very likely to be caught as bycatch. Luckily, directed fishing has been suspended, which does provide some hope for this helpless shark, but they still continue to be caught as bycatch. When caught, fisheries have strict rules that they must be returned to the water in a way that is least harmful. Since the fishing of the Porbeagle shark was suspended in 2013, no licenses that have been issued since that year. The population has not been estimated since 2009, but it was estimated between 197,000 to 207,000 individuals, including approximately 10,000 to 14,000 spawning females. The Porbeagles are very vulnerable to over-exploitation because they have a late age of maturity, and a small number of pups (average of 4 per litter). Sadly, the mortality rate for the Porbeagle shark is estimated at 100 tons per year (that is approximately 600-700 Porbeagle sharks per year). In addition to threats posed by fisheries, there are other human related threats. These threats include noise associated with offshore petroleum exploratory seismic surveys, and marine pollution. This species is endangered, but there are things you can do to help!
  • Learn about sharks to better understand them!
  • Reduce purchasing shark products, anything from meat to oils (found in any beauty items and health nutrition)
  • reduce your seafood consumption, this would also assist in stopping the accidental bycatch as seafood would be in less demand, so less fishing would occur.
  • In order to reduce pollution, begin your ‘Reduce, Reuse, Recycle’ regime! You have the potential to make a difference.
  • Lastly, share this with your friends and family so that can learn about this 'playful shark' that needs our help!

Swimming with Species – Orcas
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Swimming with Species – Orcas

Today’s species is the Orca!

Orcas, also known as Killer Whales, are among the best-known marine animals. They are iconic mammals of Canada’s wildlife, and hold an important symbolism among the Native communities. Orcas are super easy to identify with their unique tuxedo-like colouration and white “eye” patches. Since they live in all five oceans, we can find them to the east, west, and north of Canada! Now, we really should call them Orcas because “killer whales” is quite misleading. You see, Orcas are the largest members of the dolphin family, (not whales)! By large, we’re talking males up to 9 meters long and weigh 6 to 9 thousand kilograms, that’s 7-10 tons! Females are a bit smaller, and are about 7 meters long and 4 to 7 thousand kilos (5-7 tons). [caption id="attachment_38463" align="alignnone" width="1024"] Photo by Nicole Peshy, an Orca hunting a Sea Lion.[/caption]   Like most members of the dolphin family, Orcas are highly social. They live in groups called a pod which can consist of 10 to 40 related individuals. Research has found that there are different “types” of pods, for which scientists have used to classify and identify groups of Orcas. These are; Northern and Southern Resident type, Northern and Southern Transient type, and Offshore type. Differences between types can be subtle such as variations in vocal patterns and dorsal fin shapes, or more pronounced such as their preferred diet. Offshore and Residents Orcas will feed predominantly on fish; schooling fish for the Offshores, and coastal fish and squid for the Resident Orcas. Transient pods, on the other hand, feed almost exclusively on other marine mammals. Speaking of food, Orcas got their nicknames, killer whales, from their hunting strategy. Orcas are apex predators, or top predators of the oceans, and hunt in packs, quite fiercely. When a pod isn’t hunting, they spend time socializing with each other. They’ll travel, rest, explore, and play together. The most famous play behaviour is called breaching; when they dived out of the water’s surface into the air with leaps and twirls. In essence, they need to breach to come to the surface for respiration, but, they do so with fantastic style! Orcas aren’t the only ones though, most whales and dolphins perform these jumps, twirls and tail slaps. In addition, Orcas communicate with echolocation, which mean the use of sound waves to locate and identify objects within their surroundings. This helps them navigate for foraging and just for an Orca to tell another Orca their location. Orcas have long lifespans! They can live up 40-50 years old. However, females tend to live longer and can reach up to 80 years of age. Both females and males reach sexual maturity in their “teens” being 12-17 years old. Pods of different families will find one another to mate with. This keeps their genetic make-up stronger, versus if they were to inbreed. The gestation period is a little more than a year with 17 months. Babies are born with the same colouration as adults, so they really do look like miniature versions of their mother! [caption id="attachment_38462" align="alignnone" width="1024"] Photo by Eileen Redding[/caption] As social animals, offspring need their mother and pod members to learn behaviours, feed, and be safe from predators. It takes about a year before a baby is weaned, therefore it is crucial that mom and baby stay together during this time. If a baby gets lost, or gets separated from their mom, they will have a high chance of dying, not knowing how to survive on their own. Once weaned, the offspring stays with its natal pod for life. Orcas intrigue scientists with their complex behaviours. They are still so much to learn about them since scientists have only be able to conduct studies close to shores, and/or in captivity. Not only are parenting behaviours observed among pods, but pod members have been observed to teach younger members foraging and hunting skills. Pods of different “types” developed their own “dialect” for whistles, calls, and clicks, which is passed on to their offspring! But most fascinating is their ability to mourn. For example, when a baby dies, a mother will carry the body for days until she has “moved on”. This has been called a “Tour of Grief”. According to the ICUN, there is insufficient data to conclude a species assessment status other than “Data Deficient (DD)”. However, Orcas are still victims to many threats, most of them human-related. For one, commercial fisheries contribute to increased accidental net entrapment and decreased prey availability to native wildlife. Oil spills and toxic build-up via human waste affects all large species like Orcas, because toxins will accumulate in dangerous amounts within their fat cells. In addition, just as there are more cars on the roads, there are more ships asea. We don’t think of it; however, water traffic affects water acoustics, which then effects echolocation for Orcas and all other species that use this method of communication! Fortunately, they are people who do not take the threat of Orcas’ disappearance lightly. Conservation organizations like Nature Canada are pressing governments to urge the continuation of research projects, recovery plans, and imply more wildlife protection. Do you want to help out but think “oh well I’m just one person, right?” Wrong! You can help! Every step counts. Become more aware of what you’re buying and try to buy environmentally friendly items. Support sites such as Nature Canada that educate the public about our endangered species and provide guides to good stewardships. Participate in Orca educational programs with your provincial wildlife organizations. And lastly, spread the word! Post, share, and tweet about saving orcas. References: http://naturecanada.ca/what-we-do/naturevoice/endangered-species/know-our-species/orca/ http://www.iucnredlist.org/details/15421/0 https://animaldiversity.org/accounts/Orcinus_orca/ https://bc.ctvnews.ca/orca-s-tour-of-grief-over-after-carrying-dead-calf-for-nearly-3-weeks-1.4049902  

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