SUPPORTING STATEMENT 1. Taxon

1、1 of 10proposal i / 2 and ii / 2proposal for inclusion of species on the appendices of the convention on the conservation of migratory species of wild animalsa. proposal: inclusion of balaenoptera edeni on appendix i and ii.b. proponent: government of australiac. supporting statement1taxon1.1classma

2、mmalia1.2ordercetacea1.3familybalaenopteridae1.4genus and speciesbalaenoptera edeni (anderson 1878)1.5common namesenglish: brydes whale; tropical whalespanish: ballena de brydefrench: baleinoptere de bryde; rorqual deden; rorqual de bryde; rorqual tropical2biological datain the one species of balaen

3、optera edeni, a medium-sized baleen great whale, there appear to be two forms. both of these have slender bodies and broad heads, dark on top and lighter beneath, with lateral ridges on the rostrum, two blowholes and three parallel ridges running from the blowholes to the snout. however, they fall i

4、nto two size-groups. the larger offshore form moves seasonally, whereas a smaller inshore form appears to be sedentary (cummings, 1985; leatherwood and reeves, 1983; best, 1977).b. edeni live for approximately 50 years. inshore forms of the species reach physical maturity at 9-11.5m, whereas the off

5、shore variety have attained the maximum recorded lengths of 14.6m (males) and 15.6 m (females) (rice, 1998). offshore females, slightly larger than males, reach sexual maturity at about 12.5m and 10 years of age, whereas males are sexually mature at about 12.2m, between the ages of 9 and 13. maximum

6、 weight is about 20 to 25 t (jefferson, leatherwood and webber, 1993).b. edeni is a lunge feeder, filtering water and prey through baleen plates, especially euphausiids, or krill. the precise abundance of b. edeni has never been well known, partly because it is easily confused with the sei whale (b.

7、 borealis). b. edeni emit powerful low frequency moans, pulses, clicks, and grunts. they also communicate by breaching. this is an agile species, which has been reported to swim at more than 10 knots while feeding, to accelerate and change direction frequently, and often rise steeply to surface, whe

8、re they often roll on to their sides and churn water. (bannister, kemper and warneke, 1996; cummings 1985). like other cetaceans, b. edeni are “k strategists,” in that they are large, long-lived and slow to mature, they have fewer, larger offspring and a high parental investment in young, and have e

9、volved in an environment with little (temporal and stochastic) variation. as an order, cetacean populations are thus not equipped to cope with and rebound from:-sudden declines in population numbers, as has happened over the past two centuries because of unsustainable hunting; or proposal i / 2 and

10、ii / 22 of 10 -detrimental environmental impacts on habitat due to anthropogenic factors from pollution, climate change, increased fishing effort, shipping traffic etc. as is currently the case.2.1distributionb. edeni is found in the indian, pacific and atlantic oceans. its habitat includes tropical

11、 and warm temperate low latitude waters around the world, bounded approximately by latitudes 40n and s (or the 20c marine isotherm). pacific ocean in the western pacific, b. edeni occur from japan to new zealand and australia. in the eastern pacific, they are found from baja california to northern c

12、hile. they are also present in the equatorial pacific. the possibility of distinct offshore and inshore forms of brydes whales in the north pacific is still uncertain, as there may be links between the offshore form from the bonin islands and inshore populations of sanriku and oshima, japan (iwc, 19

13、77; cummings, 1985; leatherwood and reeves, 1983; iucn, 1991).atlantic ocean little is known of the distribution of b. edeni in the northern part of this region. from evidence of strandings, there appears to be a resident population in the caribbean and gulf of mexico, which may extend to the atlant

14、ic coast of the usa as far as north chesapeake bay. sightings have been recorded off northern venezuela (notarbartolo di sciara, 1983), and the species was once hunted off brazil. in the eastern atlantic, they have been reported from morocco southward to the cape of good hope. they have also been re

15、ported from the central equatorial atlantic (iwc, 1977; cummings, 1985; leatherwood and reeves, 1983; iucn, 1991).southern hemisphere both forms of b. edeni appear off the west coast of south africa, and off the brazilian coast. the offshore form have been recorded from chile, the natal coast of sou

16、th africa and western australia. the year-round tropical and temperate distribution of the offshore form suggests that the south atlantic, south pacific and indian oceans contain separate stocks (best, 1977; iwc, 1977; cummings, 1985; leatherwood and reeves, 1983; iucn, 1991).indian ocean the range

17、is from the cape of good hope north to the persian gulf, east to burma and south to shark bay, western australia. there are also animals in the central indian ocean (best, 1977; iwc, 1977; cummings, 1985; leatherwood and reeves, 1983).2.2populationvarious attempts by the scientific committee of the

18、international whaling commission (iwc) to estimate b. edeni populations were subject to debates over the reliability of their modelling and assumptions. until the 1970s, catches of b. edeni were recorded with those for b. borealis. hence, it was very difficult to separate the statistics of past oper

19、ations, in order to derive population estimates and/or catch quotas. further, the scientific committee has agreed that this species taxon “is highly complex and more work is needed (iwc, 1998a).the iwc is not currently prepared to give an abundance estimate, citing a lack of detailed assessment and

20、statistical certainty. however, a rough population estimate puts the number of b. edeni at 40-80,000, but the united nations environment program (unep) notes the threat of illegal hunting and depletion of food supplies in many areas may make this figure too high.the offshore stocks in each hemispher

21、e breed in their respective autumns, making the breeding seasons of the different hemisphere stocks six months apart. thus, it seemed reasonable at first to consider the populations as separate (iwc, 1977). this idea has since been questioned several times, but the problem has not been resolved, bec

22、ause of a lack of information (iucn, 1991). 3 of 10proposal i / 2 and ii / 2northern hemisphere no information is available on the status, distribution, number of stocks or abundance of b. edeni in the indian ocean north of the equator, although in 1982 some sightings off sri lanka were reported (iw

23、c, 1983a). in the absence of significant commercial catch records or data from sightings, the abundance of north atlantic b. edeni is similarly unknown (iwc, 1979). the only information on b. edeni in the north pacific is that, for management purposes, the idea of treating them as three separate sto

24、cks was first put forward in 1979 (iwc, 1980). the status or abundance of the eastern north pacific population is similarly unknown, and in 1985, the iwc classified the east china sea population as a protected stock: a small population from which any catch poses a serious threat (iwc, 1986).western

25、north pacific given the long history of catching b. edeni in the western north pacific, various population estimates have been possible over the years. the disparity between these demonstrates the general uncertainty about the status of this species. mark-recapture data gave an adult population of j

26、ust over 32,000 in 1946, which had depleted to 23,500 in 1987. calculations based on sightings data confirmed this depletion, but arrived at different estimates of 26,000 in 1946 and just over 17,000 in 1987 (iwc, 1986). then in 1988, another analysis of sightings data gave a total population estima

27、te for both mature and juvenile animals of 18,000 (iwc, 1989). the iwc continues to debate the possibility of further sub-stocks in the region. some of which may be more depleted, and thus more vulnerable, than others (iwc, 1999).southern hemisphere population estimates for the southern hemisphere a

28、re unreliable, for they were derived mainly from sightings data from whaling fleet scouting vessels. since the raw data have not been published, it has not been possible to reanalyse them using modern techniques (iucn, 1991).a cruise in 1983 provided data for a provisional population estimate for th

29、e south african inshore stock of 519 (s.e. 84). the eastern north pacific population (the peruvian stock) was seriously depleted, to as few as 1,400-2,400 adults in 1983 (iucn, 1991). estimates for the southern indian ocean, an inshore population in the solomon islands, and the western south pacific

30、 stock, are all considered unreliable (iucn, 1991). the iwc imposed zero catch limits on these populations in the 1980s, in the light of the inadequate estimates.2.3 habitatb. edeni may be found in temperate to tropical waters, both oceanic and inshore, bounded by latitudes 40n and 40s, or the 20 is

31、otherm. this species is usually seen singly or in small groups of up to seven animals (rice, 1979; kuzmin, ivashin and vladimirov, 1979; cummings, 1985).the trophic habitat of b. edeni is indicated by dives of up to 300m, and up to 20 min in duration.it appears that inshore populations may breed thr

32、oughout the year, and thus their critical breeding habitat includes their whole range. pelagic stocks mate and calve in autumn and winter, and thus their critical habitats are towards the equator. gestation lasts about a year, lactation probably less than a year, and the typical calving interval is

33、two years. while newborn calves are born in temperate and tropical waters, the exact locations have not yet been identified.2.4 migrationsthe larger pelagic forms of b. edeni, like other baleen whales, move annually between warmer and colder seas. in each hemisphere, the species makes a generalised

34、movement towards higher latitudes to feed in their respective summers, and a corresponding movement towards the equator to breed in winter. these migratory routes are somewhat shorter than other balaenopterids, remaining within the 20 isotherm.proposal i / 2 and ii / 24 of 10 3threat data3.1 direct

35、threats to the populationsthe international convention for the regulation of whaling allows parties to issue permits to kill whales for scientific research. since 2000, the jarpnii program has authorised japanese whalers to take 50 b. edeni from the western north pacific per year for scientific purp

36、oses. this program killed 43 whales in 2000 and 50 in 2001. the species was a focus of neither the early nor the modern whaling industry. however, the sei whale was, and it is likely that reported catches of sei whales included b. edeni. in the eastern south pacific, as many as 90% of the “sei” whal

37、es in chilean catch reports may have been b. edeni (gallardo, arcos, salamanca and pastene, 1983). an estimated 10% of those taken by the brazilian land station from 1947 were b. edeni (iwc, 1980a). japanese coastal operations record catches from the east china sea from 1955, and the south african s

38、tock was exploited from 1950 to 1967. early land and pelagic whaling operations by various countries hunting larger species in tropical and warm temperate waters also caught this species incidentally (tonnessen and johnsen, 1982; bannister et al., 1996). interest in direct exploitation of b. edeni r

39、evived in the face of diminishing quotas for the more favoured baleen species during the 1970s. the iwc fully classified southern hemisphere b. edeni stocks and set catch limits in 1979 (iwc, 1980). in 1980, the iwc allowed a catch of up to 197 per year in the indian ocean (iwc, 1981). the iwc gradu

40、ally reduced the catch limit for the east china sea stock from 19 in 1979 to zero in 1983 (iwc, 1984).however, this species demonstrates the difficulty of imposing catch limits. operations from the philippines and probably taiwan took this species from the western south pacific stock without reporti

41、ng their activity (iucn, 1991). the action plan for australian cetaceans (bannister, kemper and warneke, 1996) identifies entanglement in fishing nets as posing a threat to b. edeni.unregulated whale watching also places stress on b. edeni individuals and groups. this is a rapidly growing industry t

42、hat range states need to regulate, because at certain proximities and intensities, operators and tourists will interfere with critical breeding and socialising behaviour (gordon moscrop, carlson, ingram, leaper, matthews and young., 1998).b. edeni is also susceptible to pollution. the increasing vol

43、ume of marine debris, particularly buoyant and synthetic items such as plastic, may threaten this species through the possibility of entanglement and ingestion. substantial volumes of rubbish discarded by humans have been found in the stomachs of stranded whales (laist, knowlton, mead, collet and po

44、desta., 2001). further, oil spills and the dumping of industrial wastes into waterways and the sea lead to bio-accumulation of toxic substances in the body tissues of the top predators, making such events dangerous to great whales (cannella & kitchener 1992; iwc, 2000a).chemical pollution, in pa

45、rticular the persistent organic pollutants including pcbs, ddts, pcdds, hcb dieldrin, endrin, mirex, pcds, pbs, pedes, polcyclic aromatic hydrocarbons and phenalos as well as metals and their organic forms methyl-mercury and organotins are of concern for marine mammals in the marine environment. man

46、y of these pollutants can cause immune suppression, making them more susceptible to prey depletion, habitat modification, environmental changes (including global warming or ozone depletion) or disease. synergistic and cumulative effects must be considered in the assessment of any risk to individual

47、species or populations. (reijnders & aguilar, 2002), currently marine mammals in mid-latitudes (industrialised and intense agriculture use) of europe, north america and japan have the highest loads. however levels of organochlorines are declining in the mid latitudes and are predicted that in th

48、e near to midterm future the polar regions will become the major sinks for these contaminants. (reijnders & aguilar, 2002). of the 2 million 5 of 10proposal i / 2 and ii / 2tonnes of pcbs that have been produced world wide, only 1% has reached the oceans at this stage. around 30% has been accumu

49、lated in dump sites and the sediments of lakes, estuaries and coastal zones and future dispersal into the marine environment cannot be controlled (35% are still in use) the open ocean water serves as the final reservoir and sink for the worlds pcb production. (reijnders 1996).levels of pcb and ddt h

50、ave been detected in b. bonaerensis and appear to vary depending on geography and diet, with adult migrating to less polluted areas. (reijnders & aguilar, 2002)3.2 habitat destructionat the 50th meeting of the iwc, the scientific committee identified “environmental change” as the looming threat

51、to whale populations and their critical habitats. this meeting discussed the impact of climate change, chemical pollution, physical and biological habitat degradation, effects of fisheries, ozone depletion and uv-b radiation, arctic issues, disease and mortality events and the impact of noise and re

52、solved an ongoing work program for continued investigation (iwc, 1998b).3.3 indirect threatsglobal environmental change is an indirect threat to b. edeni. springer (1998) concluded that fluctuations in marine mammal populations in the north pacific are entirely related to climate variations and chan

53、ge. one of the more important impacts of a changing climate on marine mammals is changes to the abundance of and access to prey. this has a particularly detrimental impact on marine mammals that feed from the top of the food chain, such as whales (ipcc, 2001). further, global warming appears to be r

54、elated to reductions in sea ice: one study concludes that the antarctic sea-ice receded by 2.8 degrees latitude (168 nautical miles) between 1958 and 1972 (de la mare, 1997). this would have interfered with the feeding patterns, as well as altering the seasonal distributions, geographic ranges, migr

55、ation patterns, nutritional status, reproduction success, and ultimately the abundance of marine mammals (tynan and demaster, 1997).3.4 threats connected especially with migrationswhile migrating between feeding and breeding grounds, b. edeni are susceptible to shipping strikes. the increase in ocea

56、nic traffic increases the likelihood of collision with large vessels on shipping lanes in critical species habitat beyond the edge of continental shelves. underwater noise pollution is often a direct threat to migrating cetaceans, given their reliance on sound for navigation through their highly dev

57、eloped echolocation systems. b. edeni are particularly sensitive to low and moderate frequency sounds, from approximately 12hz to 8khz (richardson, greene, malme and thomson, 1995). it is difficult to identify conditions under which b. edeni is particularly sensitive, given the varying acoustic tran

58、smission conditions from shallow water to deep, and relative to the animals position within a water column. however, a number of anthropogenic sound sources are known to produce underwater acoustics within the frequency range of b. edeni, and potentially within migratory routes. for example, seismic

59、 operations may disturb the movements and natural activities of the species through the production of continuous, high-level, low-frequency (below 1khz) sound (wrsig and richardson, 2002). most baleen whales continue normal activity up to 150db re 1 pa, but, as these levels are some 50+ db above typ

60、ical ambient noise levels, lower received levels may have subtle effects on surfacing and respiration (richardson, et al, 1995).military activities that produce significant underwater sound pressure may also potentially interrupt whales movements and natural activities, including critical migratory, feeding and br