Whale Biological Information
The humpback whale is the fifth largest of the great whales in the world. Its scientific name, Megaptera novaeangliae, is derived from its general appearance, both physically and geographically. Megaptera, from the Griek roots megas which means big, and pteron which means wing or fin, refers to the humpback´s long pectoral fins, which is a unique characteristic of this species, since no other whale has such big fins. Novaeangliae, from the Latin root novus which means new and from the latinization angliae in reference to New England coastal waters where humpbacks were described for the first time.
Type of Whale
Humpback whales belong to the Order Mysticeti, which means baleen whales. Baleen whales have no teeth, instead they have baleens that are made out of keratin, like our fingernails, that hang from the upper jaw and are used to filter their food (Figure 1). Within the Mysticetes, Humpbacks belong to the Family Balaenopteridae or rorquals, like the blue whale, the biggest animal that exists in the planet. Rorquals distinctive feature is that they have a sleek body form and ventral grooves that work as an accordion that expands when they are feeding, so they are able to get into their mouths and throats huge amounts of water in just one mouthful.
Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Subclass: Eutheria
Order: Cetacea
Suborder: Mysticeti
Family: Balaenopteridae
Genus: Megaptera
Species: M. novaeangliae
Humpback Facts
Specieas: Megaptera novaeangliae
Gestation: 11 - 12 months
Birth Length: 1.5 tons
Adult Length: 43 - 50 ft
Adult Weight: 30 - 50 tons
Estimated Lifetime: 50+ Years
Blow: 8.2 - 10 ft
Dive: 3 - 10 min average
Speed: 2.4 - 8.6 mph
Diet: Sardines, herring & krill
Morphology
The humpback whale doesn't have a “hump.” Its name derives from its diving technique. When it dives, the humpback arches its back sharply and displays the prominent dorsal fin, giving the impression of a huge hump.
Its average longitud is 14 to 16 mt. (46 to 53 ft.), and the biggest humpback registered was 18 mt. (60 ft.) long (Clapham, 1996). It´s weight varies from 30 to 50 tons, depending on the seasonal variation of blubber.
Humpback Whale Head
The humpback’s head is proportionately bulkier than that of other rorquals, and the line of the mouth is more contorted. The lips, the chin, and entire snout are studded with fleshy protuberances, or tubercules. A single, coarse bristle grows out of the center of each of these knobs. These bristles are 3 cm. (1.8 in.) long and are believed to be very sensitive and are important within the mother-calf relationship. They are also useful for perceiving temperature changes and current direction.
Its thick, spongy tongue is sometimes coated with asperities. There are 250 to 400 pairs of dark gray baleen plates. Each is narrow and short, with a maximum length of just over 80 cm. (2.6 ft.). Humpbacks have only 14 to 35 throat grooves, set widely apart and extending all the way to the navel (Guerrero, 2005).
The enormous pectoral fins of the Humpbacks range in color from light gray to white and black to snow-white. These flippers can measure up to one-third body length (5 mt. or 16.5 ft.). They are very flexible and seem to be very important tactile organs, each of which presents from 9 to 10 protuberances (True, 1904). This special characteristic gives the humpbacks its scientific name.
Their fluke or tail lengths 4 to 5 mt. (12 ft.). Its broad, deeply notched, with serrated or frayed rear margins, and sharp white markings on the undersides, which can be seen from the surface when a Humpback is going for a deep or longer dive, is unique for each individual and is used for identification purposes (Katona & Krauss, 1970).
Females tend to be 1 to 1.5 mt. ( 3.3 to 5 ft.) bigger than males (Chittleborough, 1965). Male humpbacks tend to have more scars on their back than females, and these scars seem to be acquired with age. The increased incidence of scarring among adults is most likely due to behavioral differences between sexes. Since males get into aggressive fights in order to be able to mate, they are prone to get more scars.
The secret of the whale's swimming prowess lies partly in overall morphology. Typically these mammals swim with a smooth, measured, up and down motion, unlike fish, which move their bodies from side to side. The fluke is a powerful propeller, but it's also an instrument of stabilization and steering. The exceptional fluke power also allows Humpbacks to make spectacular breaches, so distinctive of this species.
Physiology
The Skeloton
The bones of whales are designed not so much to support the weight of organs (which are nearly weightless in water) as to serve as anchorages for muscles. Sturdiness is essential, but the bones must also be light, that way they do not increase the average density of the tissues they structure. Birds, have light, hollow bones penetrated by air sacks, which allows them to fly effortlessly. The bones of whales, are lightened in much the same way so they can swim easily. Whales bones hard, dense shell covers a spongy, weblike inner structure irrigated by blood vessels. The interstices are filled with a marrow that has very high oil content. Fully one-third of all the oil whalemen extract from their quarry comes from the bones, and those bones that are richest in marrow actually float on the surface. Thus a whale´s relatively light skeleton accounts only 17% of total body weight. For a 50-ton humpback whale that comes to about 8.5 tons (Cousteau, J. & Y. Paccalet, 1988).
Breathing
Whales breath air and like other mammals that made the transition from land to sea had to adapt to breathing while swimming. The nostrils turned into blowholes and migrated backward to the top of the head, and the diaphragm had to thicken and tilt to position lungs dorsally. Moreover any connection between the respiratory and digestive tracts had to be reduced at the rear of the mouth or the way in which cetaceans ingest food would have conflicted with the way they take in oxygen.
Whales breath air and like other mammals that made the transition from land to sea had to adapt to breathing while swimming. The nostrils turned into blowholes and migrated backward to the top of the head, and the diaphragm had to thicken and tilt to position lungs dorsally. Moreover any connection between the respiratory and digestive tracts had to be reduced at the rear of the mouth or the way in which cetaceans ingest food would have conflicted with the way they take in oxygen.
When a whale exhales it produces a spout that is different for each species. A humpback spout is about 2.5 to 5 mt. (8 to 16.5 ft.) tall and it is very narrow at its base and wide at the top, and it allows us to identify them from the distance.
Diving
Usually humpbacks dive from 5 to 7 minutes, but they can stay underwater up to 30 minutes when threatened and they seldom dive beyond 180 mt. (600 ft.). Upon surfacing it takes 4 to 8 breaths when feeding and when swimming in warm tropical waters, 2 to 4 breaths (Leatherwood et al., 1983). Before starting a deep dive they arche their backs high above the surface of the water and then throw their flukes high in the air.
Swimming Speed
Humpbacks are among the slowest whales, which actually caused them many losses during the whaling era. Generally, their swimming speed is from 4 to 14 km/hr (2.4 to 8.6 miles/hr) with an average speed of 8 km/hr (5 miles/hr) reaching up to 27 km/hr (18.5 miles/hr) when they are harassed (Leatherwood, et al. 1983).
Reproduction
Sexual maturity in humpbacks is reached between 4 and 6 years, when the females are 12.1 mt. (40 ft.) and the males 11.6 mt. (38.6 ft.) long (Clapham & Mayo, 1987). They reach physical maturity when they are 6 to 10 years old (Clapham & Mayo, 1990).
Humpbacks mate and give birth in tropical and subtropical waters in the winter, and the gestation period is about 11 to 12 months. In Mexico, Banderas Bay is one of the most important coastal areas for humpbacks reproduction, and it is common to observe impressive competitive displays as well as calves playing.
Newborn calves length around 4.1 mt. (13.6 ft) and weigh around 1,400 kg. (3,080 lb.), they are true monsters if compared to humans, but they look like a tiny dolphin when compare to their moms. Nursing lasts from 6 to 11 months and calfs consume 284 lt. (75 gl.) of milk each day. At weaning they measure 8 to 9 mt. (26 to 29 ft.) (Rice, 1963).
Generally, humpbacks can get pregnant until nursing is over, so they have one calf every two years, but they can have two calfs every three years, because some females can get pregnant while nursing (Clapham & Mayo, 1987).
We don’t know precisely how long these magnificent animals can live, but their longevity is estimated from 40 to 70 years old.
Photo Identification
This technique consists of obtaining a photograph of the underside of the humpbacks´ fluke. The fluke presents a coloration pattern which varies from completely white to completely black, and has scars, lines, spots and notches that, together with its border, form and size of the central notch, provide the whale with unique characteristics distinctive for each adult individual (Katona & Whitehead, 1981). This allows scientists to distinguish one individual from another, just as with human fingerprints. Also, the form and scars of the dorsal fin can provide us with information about the whale’s identity. Taking photos of the underside of the flukes of humpback whales, beside showing the humpbacks magnificence, it provide us with useful information that is used to estimate population numbers, study behavior, birth rates, migration routes and much more, hence its importance.
 Ecotours work directly in the Humpback Whale (Megaptera novaeangliae) in Banderas Bay Photoidentification Project, known as FIBB Catalog. To date the catalog has 991 different individuals photoidentified and a database of more than 2,290 records.
Fibb Catalog
Since 1996 the institutions: Instituto Tecnológico de Bahía de Banderas and Centro Regional de Investigación Pesquera-INP Cruz de Huanacaxtle and the whale watching tour operators, have done photoidentification projects with Humpback Whales (Megaptera novaeangliae), in Bahía de Banderas, Jalisco-Nayarit, México. In an effort to obtain more complete information in behalf of the research, conservation and protection of the species, all the photos and data were gathered in the Banderas Bay Humpback Whale Photoidentification Catalog, known as FIBB Catalog. Since the different collaborators launch from different harbors within Banderas Bay (Puerto Vallarta, Nuevo Vallarta, Cruz de Huanacaxtle and Punta de Mita), at least 60% of the Bay is covered daily, with a navigation effort of minimum 12 hours, during the whale watching season (December 15 to March 30).
In November 2006 a printed version of the FIBB Catalog was issued. It includes the results of 10 years of research, and a section about the biology and behavior of humpback whales. The Catalog has a cost of $30USD plus shipping. If you are interested in getting a copy please write to fibbcatalogo@yahoo.com
If you want to know more about the conservation efforts in Banderas Bay (Puerto Vallarta and Nuevo Vallarta) please visit www.whalephoto.org
Migrations
The humpback whale is distributed worldwide and inhabits both the Pacific and the Atlantic Oceans. In the Northern Hemisphere they are found from the Equator to 70° latitude North, in Alaska, and in the Southern Hemisphere they are found from the Equator to the margin of the Antartic Ice. The reproduction cycles of the populations in the Northern and Southern Hemisphere are separated by six months so the whales don´t interact. The populations are geographically and reproductively isolated (Rice, 1974). However, documentation shows that a whale from the Antartic population crossed over the Equator and got all the way to Colombia. This opens the possibility of occassional reproduction with other populations (Stone, et al. 1990).
In the North Pacific the humpback whales feed during the summer in the Bering Sea, Alaska Gulf, Chuckchi Sea and Okhotsk Sea and towards the South up to Honshu Island in Japan and Concepcion Point and Farallon Islands in California, USA. In the winter, during the reproduction season the humpbacks concentrate in three different areas, the Northeast Pacific (Taiwan, Bonin, Ryukyu and Marianas Islands); the Central Pacific (around the main islands in Hawaii, from Kauai to Hawaii); and the Northwest Pacific (Mexico´s Pacific coast) (Rice, 1974)
Humpback whales on the wintering grounds of the central and eastern North Pacific do not seem to form a single, freely, intermingling population or stock, due to the significant differences found in mitochondrial DNA haplotypes betweeen Hawaii and Mexico (Medrano et al. 1995).
In the Mexican Pacific waters there are four different mating subregions:
1. Baja California Peninsula, from Isla Cedros in the west coast, bordering the south corner of the peninsula all the way to Loreto on the east coast, inside the sea of Cortes.
2. Mexico’s West Coast, from Mazatlán, Sinaloa in the North, all the way to Oaxaca, and even Costa Rica, but with bigger concentrations around Isabel and Tres Marias Islands, Nayarit and Banderas Bay, Nayarit-Jalisco.
3. Revillagigedo Archipielago, Mexican oceanic islands in front of Colima.
4. North of California’s Gulf. (Urbán & Aguayo, 1987; Rice, 1974).
For the wintering grounds of Banderas Bay, Isabel Island and Baja California, the Farallon Islands (Central California), Oregon and Washington have been proven to be the main migratory destinantion in summer. Whales from Hawaii and Revillagigedo travel mainly to all of the feeding grounds in Alaska (Southeastern Alaska, Yakutat Bay, Prince William Sound, and Western Gulf of Alaska) (Baker et al. 1986; Urbán et al. 1987).
During migration, there is a temporal segregation between the animals. The beginning of the female migration is closely related to their reproduction status, more than to its age or size (Ladrón de Guevara, 2001). The first whales to arrive to the summer grounds are the pregnant females, followed by young males and females. Next in the migration are the mature males and females, and the last ones are the females with calves. Females with calves are the first ones to migrate back to the wintering grounds, followed by young females and males, sexually mature males, females and pregnant females (Dawbin, 1966). When the whales migrate from their feeding grounds to the wintering grounds they travel far away from the coast in waters with more than 200 mt. (660 ft.) deep. In the journey back to the feeding grounds they travel through coastal and shallow waters within the continental platform.
A minimum of 300 humpbacks visit Banderas Bay each wintering season. Mothers with calfs tend to be in areas closer to the shore at 1 to 4 km. (0.60 to 2.5 mi.) from the coastline. Whales without calfs tend to be 10 km (1.5 to 3 miles) away from the coast and in waters from 500 to 1,000 mt. (1,650 to 3,330 ft) deep (Ladrón de Guevara, 1995).
Behavior
Humpback whales are considered to be the most acrobatic of whales, because of all the different displays they do underwater and on the surface.
Why do Whales breach?
Breaching is one of the most impressive displays a humpback can do, is almost certainly the most powerful single action performed by any animal. Each leap is the equivalent of raising 500 persons weighing 70 kg (154 lb.) each. Every time it breaches, a whale the size of a humpback burns about 2,500 kilocalories (the daily caloric intake of an adult man). Humpbacks can breach completely out of the water, breach taking just half of their body out of the water, breach on their sides, to the front, on their back, on their bellies or spinning. Also they can take just their head out of the water to take a look at their surroundings, a posture known as "spyhopping". Sometimes they hit the water surface with their fluke, or with one or both pectoral fins (Leatherwood et al. 1983 & Whitehead, 1985)
 These displays can have different meanings, it can be intented as an act of challenge or show of strenght, its also considered as a playful or scratching activity, but it can also work as a way to get a message across to other whales, which will be especially useful when high winds or rough seas interfere with their ability to locate one another by underwater sound emission.
How do Whales sleep?
Whales have been found to sleep just under the surface with their eyes closed, their body completely relaxed and almost not moving, in a position called “logging”. They take several short naps during the day and night which is very different from other mammals, who sleep just once and for longer periods. Whales and dolphins control their respiration, so if they fall sound asleep they could suffocate (Carwardine et al. 2002).
Relationship with other Cetacions
Even though defensive behaviors, nursing, calfing, and mating behaviors provide some insights into the social organization of whales, an overall understanding of whale societies is very general, especially for baleen whales.
Baleen whales are solitary animals but it's common to find them in small groups of three to four whales. During the feeding and reproduction seasons groups from eight to fifteen animals may be seen.
Observations in Alaska suggest that humpbacks may assist each other in defensive actions. Researcher Dan McSweeney watched four adult humpbacks rush to join a cow and a calf under attack. The calf was protected while the humpbacks used their tails to fend off the killer whales. After the attack, one of the humpbacks had a piece of flesh stripped away and was bleeding badly; another had part of its tail torn off, the calf and the cow appeared to be uninjured (Nicklin et al. 1990).
Observers have seen Humpbacks in Banderas Bay along with different kinds of dolphins, including the bottlenosed dolphin (Tursiops truncatus), the rough-toothed dolphin (Steno bredanensis), and the spotted dolphin (Stenella attenuata) (Salinas & Bourillon, 1988). It's thought that dolphins enjoy playing with the whales' pressure wave that provides propulsion similar to when they play with waves caused by boats. In Isla Socorro and Hawaii, scientists have seen humpbacks launching bottlenosed dolphins out of the water with their heads. The bottlenosed dolphins come back to the whale and swim close to its head so they can be launched again.
In other regions, Humpback whales have also been observed interacting with common dolphins (Delphinus delphis).
In their mating grounds
The complex behavior of humpbacks in their mating grounds is all product of the need to mate, calve and rear offspring. Winter grounds appear to be chosen more for physical rather than biological characteristics. Important factors in site selection seem to include what is best (in terms of energy conservation and protection from predators) for the mother and the newborn. For this reason, the areas are warmer, shallower and more protected than summer feeding grounds. The winter migration and assembly also serves to bring together males and females who often separate in the summer (Nicklin et al. 1990).
While in their mating grounds humpbacks appear to show little site fidelity, either within or across years. They do not appear to show stable groups, with the exception of the mother and calf. In general the most frequent group size seen is two to three animals, but singles are also quite common.
As far as we know the Humpback male is the only great whale that gets into aggressive physical competitions in order to be able to mate. Sometimes they gather in big groups than can range in size from three to fifteen, even twenty whales, these groups are called “mating or competitive groups” and the mayority of the whales are males charging around a female, the “nuclear animal.” Sometimes the nuclear whale is a single adult female, sometimes a cow with a calf.
 The males in the group compete for the position next to the nuclear animal. The male closest to the female, the “principal escort”, vigorously defends this position against all challengers. The principal escort, the nuclear animal, and her calf, if present, form a central group around which all the other males, called “secondary escorts”, are distributed. A secondary escort ocassionally tries to displace the principal escort. This competition is quite aggressive, it can range a wide variety of behaviors such as bubbles streaming from the blowhole, explosive blowing under the surface, and gulpping air and expanding the throat pouch, possibly to make a male look bigger. The fighting includes lashing or pummeling each other with the tail, head, pectoral fins or the whole body. The results are often bloody head, dorsal fins or fluke wounds. If successful, the challenger becomes the new principal escort, but such takeovers are rare, and most secondary escorts remain as secondary escorts until they leave the group. Large groups vary in size as secondary escorts depart or as new ones arrive. The principal escort remains with the nuclear animal at the end and may be the one to mate with her.
Humpbacks also appear to establish a dominance rank by displays like violent tail slashes, flipper slaps or breaches and their songs.
During the breeding season, females with calves are often accompanied by one another adult whale that has always been found to be a male. This male is usually referred to as “lone escort”. Lone escorts accompany females with calves because of the chance of being able to mate with her when and if she becomes receptive. A lone escort automatically becomes the principal escort when challenged by another male or in a competitive group.
Humpback Whale Songs
Cetaceans like all animals have had to develop a method of communication suited to their environment. At depths vision becomes limited, and trying to communicate over the tops of waves while at the surface can be extremely energy consuming, furthermore sound travels three times faster underwater than in air. While all cetaceans are able to emit sounds under a variety of conditions, the humpback whale seems unique in the complex diversity of its underwater vocalizations. Humpbacks produce a wide variety of sounds, including the highest and the lowest frequencies humans can hear, with an extraordinary range of tonal qualities. How humpbacks create these sounds is unknown since they do not have functional vocal cords. Some evidence suggests that the sounds are produced by various valves, muscles, and a series of blind sacks found branching off the respiratory tract (Kaufman & Forestell, 2002).
 Humpback songs are probably the most famous, intriguing and least typical sounds made by whales. After three decades of intensive study, the basic characteristics of the song have been clearly defined. The songs, approximately ten to fifteen minutes in duration, are sequences of sounds repeated over and over again. The song gradually changes or evolves in a fairly orderly manner as it is being sung and the changes are transmited within the males of the same population (Payne & McVay, 1971; Winn & Winn, 1978). All the singers in a particular population sing basically the same version at any one time (McSweeney et al., 1989). Singing is a primary activity of humpbacks in their winter breeding grounds, but it's heard occasionally at the end of the feeding season (Mattila et al., 1987; Straley, 1990) or during migration (Clapham & Mattila, 1990).
The typical singer is usually a lone adult male. In 1979 Chuck Nicklin filmed the first singing humpback in Maui, and it wasn't until then that singing humpbacks were positively identified as being males. Up to date we still do not know exactly why do only male humpbacks sing, but due that singing takes place mainly during the mating season, it is believed that they do it with reproductive purposes, and it could help to call the attention of the females or to limit their territory.
When singing, the whale would be motionless, head down at about a 45° angle, about 15 to 23 mt. (50 to 75 ft.) below the surface. The whale would sing for about ten to twenty minutes, surface without interrupting the song, take three or four breaths, then dive and return to the singing position. It often repeats this sequence for hours at a time. Singing during the mating season plays a very important role for the reproductive success of humpback males (Baker & Herman, 1984).
Calves
It´s generally believed that humpback calves are both conceived and born in the Mexican Pacific, since the gestation period is 11 to 12 months.
The calf’s behavior varies a lot during nursing. When new born it will stay very close to its mother to assure its protection. Usually, after a month, it becomes very playful and restless, it starts breaching, slashing its tail and flippers. This will provide it with enough strength and neuromuscular coordination for the long trip to the feeding grounds and is also important within its social formation. Then, just a few weeks before starting the migration, its activity slows down and usually it stays very close to its mother, assuring its safety during the migration trip.
Mother whales often “carry” their young with them as they travel. The mother creates a pressure wave as she swims, and the young calf effortlessly takes a ride. Very young calves are not fast swimmers, however, they learn early in life that hitching a ride on the pressure wave allows them to keep up with the adult whales.
In their Feeding Grounds
Humpbacks feed mainly on krill (Gendrón y Urbán, 1993) and schools of herring, anchovies and codfish (Rice, 1963). When feeding, they can open their mouth up to 90 degrees, but they can’t eat anything bigger than a baseball. Usually each whale eats up to one ton of food per day.
Different species of whales have different feeding strategies. Feeding strategy governs the lifestyle of the animal, dictates distribution, behavior patterns, social organization, communication, and ultimately physical appearance. What they are physically and behaviorally has been determined by their finding the best way to capture and most efficiently use for their food. Only the extravagances of sex or the needs of self protection break this rule.
The three different families of baleen whales: Eschrichtiidae (gray whales), Balaenidae (bowheads and right whales) and Balaenopteridae (rorquals), employ three general feeding styles. Primarily bottom feeders, the gray whales plunge their heads into the mud, take a giant mouthful and filter the bottom-living organisms from the mud and water. Right and bowhead whales are skim feeders and essentially swim through swarms of plankton with their mouths open. The third group, including humpbacks, blues, fins, seis, brydes and minkes (all rorcuals with huge throat grooves, which extend as an accordion when feeding), are generally known as gulpers, taking huge gulps of water and food, and filtering it. These different feeding strategies reflect the type of food eaten, but of course there are exceptions (Nicklin et al. 1990).
Among baleen whales, humpbacks have very specialized strategies for feeding, which varies depending on the amount and kind of food to be eaten:
1. Assail: The humpback approaches its food from the bottom or from the side with its mouth wide open and gulping the food.
2. Slash: This consists of fast and precise tail movements that causes a forward current which seems to concentrate krill or fish right in front of the whale, which just swims forward gulping it.
3. Bubble-netting: Humpbacks literally blow nets made of air bubbles. “Like a gigiant undersea spider spinning its web,” writes Roger Payne (1979), “the humpback begins perhaps 165 mt. (50 ft.) deep, forcing bursts of air through its blowholes while swimming in an upward spiral. Big bubbles, followed by a mist of tiny ones, rise to create a cylindrical screen that concentrates krill and small fish. Bubbles and food pop up to the surface, followed by the gaping mouth of the whale as it emerges in the center of its net.” There are times when two or more whales work together, this process is amazingly deliberate and methodical. A lot of coordination is required, with whales working as a team and each keeping their own place in the feeding area all the time. Sometimes a whale emits a special call that's used to help sinchronize the feeding and disorient the fish. They can built nets that can stretch as much as 30 mt.(100 ft.) across.
Humpbacks Today
“Whales are a barometer of the state of the ocean. They integrate what is going on over a long period of time and over great distances. They tell us something very important. Sometimes, we have to be a little bit sensitive to see it, or somewhat clever, but the message is there. If the whales are having troubles, the ocean is having troubles, and if the ocean is having troubles, we are having troubles” Steve Katona (1988).
Actual Status
It´s estimated that the world Humpback whale population before the commercial whaling was of 125,000 individuals. In 1984 no more than 10,000 to 12,000 humpbacks existed (Braham, 1984), nearly 10% of the original population (Urbán et al. 1999). Just in the North Pacific, the population prior its commercial exploitation was estimated in 15,000 to 20,000 whales (Rice, 1978), and after the ban on commercial whaling in 1966, only 1,400 to 1,200 whales were left (Gambell, 1976; Johnson & Wolman, 1984, respectively). By 1977 Calambokidis et al. determined a population abundance of 8,200 Humpbacks in the North Pacific, which included the Mexican Pacific (2,700), Hawai (5,000) and Japan (500), showing a recovey in the population numbers, nevertheless still quite low considering the population numbers prior to its exploitation.
Recent studies estimate that that there might be aproximately 2,000 humpbacks in the Gulf of California. This “coastal stock” is integrated by whales that are distributed along Mexico continental coastline (Bahía de Banderas, Chamela, Isla Isabel e Islas Marías) and by the whales distributed around Baja California Peninsula, from Bahía Magadalena in the west coastline to Bahía de La Paz in the sea of Cortes. In 1992, the population abundance for this stock was 1,813 (CI: 918-2505) (Urbán, 2001). In 2004, Frisch estimated that only in Banderas Bay the population abundance might be 750 to 2,200 individuals.
Conservation
The International Whaling Comission (IWC) was established in 1946 to regulate whaling. In 1949, Mexico starts participating in the international agreements for the regulation of commercial whaling at the IWC. Humpback whales were the second species to be protected by the IWC, when in 1955 the ban on commercial whaling was installed in the North Atlantic (substenance whaling is still allowed) (Katona, 1991). This protection was extended to the North Pacific in 1966 (Winn y Reichley, 1985). Since commercial whaling diminished so badly the population numbers in all its distribution areas, humpbacks were listed as “endangered” in the United States (Braham, 1984), as “threatened” in Canada (Whitehead, 1987), as “endangered” in the International Union for the Conservation of Nature (IUCN) (Klinowska, 1991) and appears in the Appendix I of CITES convention, of which Mexico is member since 1984. In the Mexican NOM-059-SEMARNAT-2001 it´s listed as “under special protection” (Guerrero, 2005).
In June 2006, for the first time in 20 years, Japan gets enough votes (33 in favour, 32 against and 1 abstention) to make the IWC declare that the 1986 moratorium on commercial whaling is unnecessary and blaming whales for depleting fish stocks. This controversial decision is very bad for whales conservation. Nevertheless there´s still hope, Japan and the pro-whaling countries need to gather 75% of the votes at IWC in order to be able to reopen commercial whaling again.
Even whales are recovering, population numbers are far from what they used to be before commercial whaling. Besides whales are not afraid of boats anymore, every year they get more accustomed to whale watching boats, and instead of avoiding the boats, some whales approach them in a curious manner. A good example are gray whales, which occasionally bring their calves to the boats and people can pet them. Now that whales do not elude boats any more, do we have the right to hunt them again? Furthermost the whale watching activity just in Banderas Bay produces an income of approximately $8,000,000US each year (Beets, 2006), proving that whales worth more alive than dead.
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