Whales Dolphins

Whales & Dolphins: 

Whales & Dolphins Janae Barrett Based on NEAq resources & Lowell lectures given by John Calembokidis & Dr. Scott Kraus

Figure 9.1: 

Figure 9.1

Classification: 

Classification Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Cetacea Suborder: Odontoceti- toothed whales: dolphins, porpoises, sperm whale, killer whale, pilot whale & beaked whales 1 blow hole opening Suborder: Mysticeti- baleen whales Baleen is made of keratin 2 blow hole openings

Evolutionary History: 

Evolutionary History Evolved from land-dwelling ancestor First mammals arose in Cenozoic Era 65 mya First whales appear – 60 mya Seals and walruses – 30 mya Sea otters – 5 mya

Figure 9.18: 

Figure 9.18

Figure 9.25: 

Figure 9.25

Echolocation: 

Echolocation

Figure 9.31: 

Figure 9.31

Diet of Great Whales: 

Diet of Great Whales

Impact of Whaling : 

Impact of Whaling

Conservation: 

Conservation Some species fall under the National Endangered Species Act, 1973 All fall under the jurisdiction of the Marine Mammal Protection Act passed in 1972 States it is a federal offense to kill, capture, & disturb any marine mammal

Slide14: 

Right Whales: the ‘Right’ whale to hunt Why the ‘RIGHT‘ Whale? -Live close to shore -Floated after killed -Yielded much oil & long baleen plates

History: 

History Began hunting them 1,000 years ago By 1788, British, French and American ships were hunting the Southern Right whales off the South African coast. Over the next 30 years an estimated 12,000 whales were killed Last right whale killed in US, FL- 1935 Really none left in eastern N. Atlantic Individuals have been tracked over time spanning whaling & whale research eras because they are so recognizable Research began in 1979 in Gulf of Maine NMFS surveyed for potential oil refinery in Eastport Harbor, ME Found there were far more right whales than they expected Oil refinery never built

Cataloging Whales: 

Cataloging Whales Calluses form patterns on head/nose 1. broken callosities 2. continuous callosities 3 main areas Eyebrow Chin Nose Whales are given number identification and sometimes names based on the pattern of calluses

Slide17: 

Callosities -located on head of right whales identifies individuals & helps to give them names.

Research Methods: 

Research Methods 1. Aerial & shipboard photo identification Research trips 1980 Bay of Fundy 1983 Scotia Shelf 1984 Southeast US Gather data on distribution, abundance, births, deaths & movements Have researched historical whaling grounds of Labrador, Greenland, & Iceland Not many right whales found in these areas Appears they have avoided these regions

Slide19: 

Right Whale Breaching

Movements: 

Movements Winter: SE US, for calving, about 1/3 of pop. Spring: Cape Cod Bay & Great South Channel, for spring feeding, about 2/3 of pop. Summer/ Fall: Bay of Fundy & Scotia Shelf, about 2/3 of pop. About 1/3 of pop. is always missing Where do they go? Maybe another summering ground?

Slide21: 

Right Whale mother & calf

More Research Methods: 

More Research Methods 2. Biopsy darts Only take a sample of blubber Genetic info: sex & family relationships b/c of small pop. Size Contaminants Overall health of individual 3. Ultrasound device (just like human prenatal care) Nutrition & general health Blubber thickness changes as females become pregnant, give birth, & lactate

More Research Methods: 

More Research Methods 4. Fecal Sampling Began after decline in reproduction in 1990’s Fecal masses float in large fields on surface Info on red tides or other biotoxins Disease & parasites Reproductive hormones Stress & general health

Results of Research: 

Results of Research One of the best known wild populations in world Genetic profiles of many indiv. to construct family trees Low genetic diversity (not as low as cheetahs) makes pop. vulnerable to crash At least 5 reproductive females made it through the population bottleneck following whaling

Current Population Size: 

Current Population Size About 350 individuals in N. Atlantic! Problem: small pop. size cannot provide good statistics to make predictions about this pop. Isolated from all other pops. Can’t cross equator b/c thick blubber Other pops.: North Pacific (western region) & southern hemisphere N. A. pop. declining in size due to less reproduction & increased mortality due to shipping & fishing Many females not calving, why? 2002- 31 calves, but decline over past 2 years Over the past 20 + years average 12 calves/ year Spike years and then steady decline until another spike in # of calves Females give birth every 3 to 6 years- low reproductive rate

Protection: 

Protection MMPA- marine mammal protection act Endangered Species Act protects critical habitat for these whales- calving grounds 2 regions in Canada 2 regions in US: SE US & Cape Cod Bay

Why low reproductive rate?: 

Why low reproductive rate? Feeding & nutrition: #1 factor that influences reproduction in mammals Contaminants: eat mostly copepods- low on food chain- little bioaccumulation Disease & parasites Genetics & potential inbreeding Habitat requirements- is it just food that matters or are factors like ambient/ human noise disrupting their communication & behavior?

Mortalities: 

Mortalities 1974-2002: 62 deaths 22 from ship collisions 6 from fishing gear 72% of all right whales have gear entanglement scars- fostered new research with fishing industry to develop new equipment/ techniques Human causes 45% 17 unknown cause: 27.5% 17 natural causes: 27.5% Not all deaths accounted for

Changes in US: 

Changes in US 2003 moved shipping lanes in Bay of Fundy to better avoid areas where right whales congregate in spring, summer, fall Parties involved: Canada, US, Irving Oil, Dept. of Fisheries, & NEAq Hit by ships because they are surface feeders & conduct courtship rituals at the surface Result: 95% decrease in probability of a collision with a right whale

Slide30: 

Right Whale showing skimming feeding behavior Unlike many other baleen whales, Right whales do not have dorsal fins or pleated throat grooves.

Yearly Travels of the Urban Whale: 

Yearly Travels of the Urban Whale Calf born in Jan. off FL/ GA coast Close to shore- about 40 miles offshore 3,000 ships in/out per year in this area Paper mill emissions = acid rain offshore Late Feb./ March begin migration north within 40 miles of shore always Pass by 12 major cities/ ports with lots of agricultural runoff & shipping noise Norfolk & Chesapeake Bay  Delaware Bay loaded with fishing gear and shipping traffic NYC harbor: pharmaceutical runoff= hormones increase in effluent, not treated in sewage = birth control hormones in ocean! Is this affecting the whales? Providence Buzzards Bay  Cape Cod Bay  Gulf of Maine  Bay of Fundy: drastic increase in fishing gear and ship traffic in summer months when they are up in this area

Slide32: 

The Blue Whale The Largest Creature to live on Earth

Slide33: 

Balaenoptera musculus

Cascadia Research on the Blue Whale: 

Cascadia Research on the Blue Whale Began research in 1986 while studying Humpbacks off of CA Big target in commerical whaling, thought to be virtually wiped out Led to long term research in Pacific Types of data collected: Photo ID Tagging Feeding Abundance Movements Vocalization recordings

Slide36: 

Not much of a catalog of indiv. unlike many other whale species

Research Methods: 

Research Methods Use small boats- 20 ft or less Lower cost Maneuverable Quick to relocate Ability to approach closely Research area: from British Columbia to Baja Photo ID Most photos of tail fluke & mottling pattern on dorsal side and fluke Have identified a pale while indiv. –not sure if it’s an albino

Where are the Whales?: 

Where are the Whales? Coordinated research on Humpbacks in N. Pacific has produced much data on blue whales Research cruise found blue whales in areas that they hadn’t been typically found in for decades (former whaling grounds) Shift in migration pattern: Pre-whaling- often in Gulf of Alaska & little time in CA waters Post-whaling- shows reverse pattern Today often found in area called Costa Rica Dome off of Mexico and CR, identified area in 1999 Some stay here year-round and don’t migrate CA blue whales migrate here for winter Jan-March: about 1400 June- August: about 200-600 About 1500 indiv. identified in CA waters May be whales migrating here from S. Pacific & Southern Ocean Total estimate in Eastern N. Pacific- about 2,000- much more than previously thought!

Slide40: 

NOAA map of blue whale tags in Pacific Northwest

Vocalizations: 

Vocalizations Largest animal on Earth= loudest low frequency sounds- most of it we can’t hear Can travel the longest distances- 1,000 km! Call Types: A – deep, low, repetitive thudding B – low, descending rumble D- short, low rumble A & B- mostly males D- both genders, assoc. with feeding We can identify the whale species by the song, but it’s harder to determine the indiv. based on the song To solve this problem: tag the animal and record songs What does it mean when they aren’t calling? Why does call rate/ types vary through the year? – trying to answer these ?s by correlations to behavior

Blue Whale Songs: 

Blue Whale Songs Some whales call regularly- very few do this Mostly migrating individuals, not feeding Most whales are irregular callers b/c most are engaged in feeding Harder to call when engaged in deep diving Very little air to produce a sound

Sonar & Vocalizations: 

Sonar & Vocalizations Navy’s low freq. sonar is in this range- may affect whales? Navy hydrophone techs were 1st to hear & describe whale songs & determine they were, in fact, made by animals Air gun array produces 263 dB LFA- low frequency active- 240+ dB Navy mid-freq. sonar- 235 dB Has been implicated in mass strandings of Cuvier’s beaked whales in 1996 & 2002

Slide45: 

Aerial View of a Blue Whale Blue Whale Breaching the Surface

Tagging Research: 

Tagging Research 1. Movement Visible tags VHF Satellite Deployed into blubber- more invasive= good tracking of a year+ in some cases 2. Behavior TDR- time depth recorders Cameras & other instruments 3. Physiological measurements 4. Acoustic Tags

More Tagging : 

More Tagging Non-invasive tag for diving= pressure sensor Nat’l Geo Crittercam: hi 8 video, hydrophone, & pressure Film 2-3 hours, releases, & pick up Secured by suction cups

Crittercam Data : 

Crittercam Data Krill usually around 60 m down in layer during summertime Records feeding/ diving behavior Whales dive below the krill & then up & down into the layer several times Dives to 300 m have been recorded Krill layer shifts during the day Shallow at night Deeper during the day Can range in depth from 300 m to 10 m

Crittercam continued: 

Crittercam continued Even though there is nothing to see on the film because there is no light at these depths the sound of water turbulence tells them what the whale is doing as far as how fast it is swimming, etc. Nat’l Geo. was disappointed with the film footage because most of diving was pitch black

Bioacoustic Senors: 

Bioacoustic Senors Stay on longer than other probes High quality audio secured by suction cups Pick up after 1 day Records depth, pitch, & roll of whale’s movements steep dive, about 80° angle, very few fluke beats- mostly gliding down must beat flukes a lot when they ascend b/c lungs are empty (=no buoyancy) lungs collapse, about 100 m, force air out of lungs & push oxygen into tissues so they can sink & glide down on the dive

Slide51: 

Just after a gulp of tasty krill in shallow water

Diving Pattern: 

Diving Pattern Shallow, resting depths at night Active diving during the day Do not participate in any kind of cooperative feeding behavior like Humpbacks & other cetaceans even when seen in male/female pairs

Slide53: 

Mother & calf from above