Smith, B. D., ,Shore, R.G., ,Lopez, A., ,Beasley, I. ,Gilbert, M., ,Sokha, K., ,Kittawattanawong, K., ,Kreb, D., ,Moelyono, H., ,Tun, M. T., ,Channy, O., ,Pattnaik, A., ,Somany, P., ,Phothitay, C., ,Sutaria, D. ,Tun, T.
Action Plan for the Conservation of Freshwater Populations of Irrawaddy Dolphins Book
Wildlife Conservation Society, 2007, ISBN: WCSWP31.
Abstract | BibTeX | Tags: Ayeyarwady River, Chilika Lake, conservation, Freshwater ecosystem management, Irrawaddy dolphin, Mahakam River, Mekong River, population estimates, Songkhla Lake
@book{,
title = {Action Plan for the Conservation of Freshwater Populations of Irrawaddy Dolphins},
author = {Smith, B. D., ,Shore, R.G., ,Lopez, A., ,Beasley, I. ,Gilbert, M., ,Sokha, K., ,Kittawattanawong, K., ,Kreb, D., ,Moelyono, H., ,Tun, M. T., ,Channy, O., ,Pattnaik, A., ,Somany, P., ,Phothitay, C., ,Sutaria, D. ,Tun, T.},
issn = {WCSWP31},
year = {2007},
date = {2007-01-01},
journal = {Status and conservation of freshwater populations of Irrawaddy dolphins: WCS Working Paper 31},
number = {477},
pages = {1-119},
publisher = {Wildlife Conservation Society},
abstract = {Freshwater populations of Irrawaddy dolphins are threatened with extinction
in the near future, and urgent conservation measures are required for their
long-term survival. In contrast to the environmental preferences of other members
of their species, which inhabit nearshore marine waters, these animals
live far upstream in three large rivers (the Mekong in Cambodia, Lao PDR
and Vietnam, the Mahakam in Kalimantan, Indonesia, and the Ayeyarwady in
Myanmar) and in two brackish lagoons or marine appended lakes (Songkhla
in Thailand and Chilika in India, Figure 1). Balancing the resource needs of
local human communities with the survival requirements of these large, mobile,
aquatic predators is a challenging task due to their restricted distribution in
freshwater bodies which are already subjected to high levels of human use. The
irony of their endangerment is that Irrawaddy dolphins are generally regarded
positively by local people, probably due to their engaging social displays, role
in cultural folklore, and in the Ayeyarwady River participation in a cooperative
fishery with cast-net fishermen. This positive attitude enhances the potential for
working with governments and local communities to find conservation solutions
and generate local revenue through sustainable tourism.
The primary threat to most populations is incidental killing from gillnet
entanglement. In the Mekong River of Cambodia gillnet entanglement accounted
for 87% of the mean yearly, confirmed human-caused mortalities where
the cause could be identified, representing at least 5.4% of the current estimated
minimum population size. In the Mahakam River, gillnet entanglement
accounted for 66% of the mean yearly recorded mortalities and 4.0% of the
estimated population size. A particular fisheries problem threatening dolphins
in the Ayeyarwady and Mahakam rivers is electrocution from illegal electric
fishing. This non-selective fishing technique may also be causing declines in
dolphin prey.
Habitat loss and degradation are caused by water developments, gold and
coal mining operations, increasing sedimentation from dredging and shoreline
development, and large numbers of fixed fishing gears that block access to large
sections of the rivers and lagoons. The effects of these factors are difficult to
quantify but may be substantial, especially when combined with mortality from
fisheries bycatch. Chemical pollution from biocides used in shoreline aquaculture
and agriculture, mercury and cyanide used in gold mining operations,
and coal spillage from transport barges may be directly affecting the health of
status and conservation of freshwater populations of irrawaddy dolphins
certain populations and indirectly affecting them due to impacts on their prey.
Vessel harassment and collisions may also be affecting some populations, particularly
boat traffic associated with dolphin watching operations in the mouth
of Chilika Lake and possibly in the Mekong River at the Lao PDR-Cambodia
transborder and Kampi pools, while large coal transport barges in narrow
tributary habitat interfere with dolphin movements in the Mahakam River.
Strategies for mitigating bycatch include: (1) establishing core conservation
areas where gillnetting would be banned or severely restricted; (2) promoting
net attendance rules and providing training on the safe release of entangled
dolphins; (3) initiating a program to compensate fishermen for damage caused
to their nets by entangled dolphins that are safely released; (4) providing alternative
or diversified employment options for gillnet fishermen; (5) encouraging
the use of fishing gears that do not harm dolphins by altering or establishing fee
structures for fishing permits to make gillnetting more expensive while decreasing
the fees for non-destructive gears; and (6) experimenting with acoustical
deterrents and reflective nets.
Multiple-use protected areas will play a key role for conserving dolphins:
(1) in the Mekong River, at nine deep pool areas between Kratie and the Lao
PDR-Cambodia border; (2) in the Mahakam River, in 10-20 km segments in
the Kedang Pahu tributary mouth at Muara Pahu Town, the mouths of the
Kedang Kepala and Kedang Rantau tributaries, and the Pela tributary including
the southern portion of Semayang Lake; (3) in the Ayeyarwady River, river
segments between the Taping river confluence at Bhamo to the upstream end of
the second river defile at Sinkan, the downstream end of the second river defile
to Tagaung, and the downstream end of the third river defile at Kyaukmyaung
to Mingun; (4) in Songkhla Lake, in the middle portion of upper Thale Luang;
and (5) in Chilika Lake, in the area between Magamukh and the outer lake
mouth.
Research and monitoring will be needed to guide and assess the efficacy
of conservation interventions. Recommended methods for abundance estimation
include mark-recapture analysis of photo-identified individuals and direct
counts that incorporate measures to reduce sighting biases in the field and
evaluate and correct them analytically. Recommended methods for evaluating
dolphin mortality include interview surveys, carcass recovery programs, and
direct counts of fishing operations known or believed to be responsible for
dolphin deaths.
Freshwater populations of Irrawaddy dolphins can still be saved if appropriate
conservation measures are urgently implemented. To conserve these populations
it will be essential to closely involve local people in the development and
implementation of conservation plans. This will require sufficient funds and
a strong commitment from national governments and local and international
NGOs.
status and conservation of freshwater populations of irrawaddy dolphins
The idea for this volume emerged from the Workshop to Develop a Conservation
Action Plan for Freshwater Populations of Irrawaddy Dolphins held 21-26
March 2005 in Phnom Penh, Cambodia. The volume aims to publicize the
Action Plan and provide science-based justifications for urgent implementation
of recommended priority actions. The volume contains the Action Plan for the
Conservation of Freshwater Populations of Irrawaddy Dolphins, Report on the
Workshop to Develop a Conservation Action Plan for Freshwater Populations
of Irrawaddy Dolphins, and reviews of the conservation status of each of the
five freshwater populations.
The Action Plan highlights common actions needed for all five populations
and more specific actions needed for individual populations. The complexity
of devising effective solutions to address the full range of threats to freshwater
populations of Irrawaddy dolphins was beyond the scope of this workshop and
also arguably beyond the capacity to finance with available funds. Substantial
progress was made, however, on formulating some practical actions that must
be taken to prevent extinction of these populations.
A recent positive development has been the substantial research progress on
assessing the conservation status of all five freshwater populations of Irrawaddy
dolphins. This has been made possible by the dedicated work of a relatively
small group of local and international scientists and conservationists who were
mostly present at the workshop. We are proud to present in this volume reports
on the conservation status of all five freshwater populations. These reports gave
us a strong foundation for productive discussions at the workshop and development
of the Action Plan. All five reports underwent peer-review and were
edited for consistency and style, but the content remained the responsibility of
individual authors.
Between the time of the workshop and publication of this volume significant
steps have been taken to implement recommended conservation actions for
some populations. To preserve the accuracy of discussions conducted at the
workshop we decided not to revise the workshop report post-hoc but to encourage
authors of the conservation status reports on each population to include
new developments in these documents, which they have done in this volume.},
keywords = {Ayeyarwady River, Chilika Lake, conservation, Freshwater ecosystem management, Irrawaddy dolphin, Mahakam River, Mekong River, population estimates, Songkhla Lake},
pubstate = {published},
tppubtype = {book}
}
Freshwater populations of Irrawaddy dolphins are threatened with extinction
in the near future, and urgent conservation measures are required for their
long-term survival. In contrast to the environmental preferences of other members
of their species, which inhabit nearshore marine waters, these animals
live far upstream in three large rivers (the Mekong in Cambodia, Lao PDR
and Vietnam, the Mahakam in Kalimantan, Indonesia, and the Ayeyarwady in
Myanmar) and in two brackish lagoons or marine appended lakes (Songkhla
in Thailand and Chilika in India, Figure 1). Balancing the resource needs of
local human communities with the survival requirements of these large, mobile,
aquatic predators is a challenging task due to their restricted distribution in
freshwater bodies which are already subjected to high levels of human use. The
irony of their endangerment is that Irrawaddy dolphins are generally regarded
positively by local people, probably due to their engaging social displays, role
in cultural folklore, and in the Ayeyarwady River participation in a cooperative
fishery with cast-net fishermen. This positive attitude enhances the potential for
working with governments and local communities to find conservation solutions
and generate local revenue through sustainable tourism.
The primary threat to most populations is incidental killing from gillnet
entanglement. In the Mekong River of Cambodia gillnet entanglement accounted
for 87% of the mean yearly, confirmed human-caused mortalities where
the cause could be identified, representing at least 5.4% of the current estimated
minimum population size. In the Mahakam River, gillnet entanglement
accounted for 66% of the mean yearly recorded mortalities and 4.0% of the
estimated population size. A particular fisheries problem threatening dolphins
in the Ayeyarwady and Mahakam rivers is electrocution from illegal electric
fishing. This non-selective fishing technique may also be causing declines in
dolphin prey.
Habitat loss and degradation are caused by water developments, gold and
coal mining operations, increasing sedimentation from dredging and shoreline
development, and large numbers of fixed fishing gears that block access to large
sections of the rivers and lagoons. The effects of these factors are difficult to
quantify but may be substantial, especially when combined with mortality from
fisheries bycatch. Chemical pollution from biocides used in shoreline aquaculture
and agriculture, mercury and cyanide used in gold mining operations,
and coal spillage from transport barges may be directly affecting the health of
status and conservation of freshwater populations of irrawaddy dolphins
certain populations and indirectly affecting them due to impacts on their prey.
Vessel harassment and collisions may also be affecting some populations, particularly
boat traffic associated with dolphin watching operations in the mouth
of Chilika Lake and possibly in the Mekong River at the Lao PDR-Cambodia
transborder and Kampi pools, while large coal transport barges in narrow
tributary habitat interfere with dolphin movements in the Mahakam River.
Strategies for mitigating bycatch include: (1) establishing core conservation
areas where gillnetting would be banned or severely restricted; (2) promoting
net attendance rules and providing training on the safe release of entangled
dolphins; (3) initiating a program to compensate fishermen for damage caused
to their nets by entangled dolphins that are safely released; (4) providing alternative
or diversified employment options for gillnet fishermen; (5) encouraging
the use of fishing gears that do not harm dolphins by altering or establishing fee
structures for fishing permits to make gillnetting more expensive while decreasing
the fees for non-destructive gears; and (6) experimenting with acoustical
deterrents and reflective nets.
Multiple-use protected areas will play a key role for conserving dolphins:
(1) in the Mekong River, at nine deep pool areas between Kratie and the Lao
PDR-Cambodia border; (2) in the Mahakam River, in 10-20 km segments in
the Kedang Pahu tributary mouth at Muara Pahu Town, the mouths of the
Kedang Kepala and Kedang Rantau tributaries, and the Pela tributary including
the southern portion of Semayang Lake; (3) in the Ayeyarwady River, river
segments between the Taping river confluence at Bhamo to the upstream end of
the second river defile at Sinkan, the downstream end of the second river defile
to Tagaung, and the downstream end of the third river defile at Kyaukmyaung
to Mingun; (4) in Songkhla Lake, in the middle portion of upper Thale Luang;
and (5) in Chilika Lake, in the area between Magamukh and the outer lake
mouth.
Research and monitoring will be needed to guide and assess the efficacy
of conservation interventions. Recommended methods for abundance estimation
include mark-recapture analysis of photo-identified individuals and direct
counts that incorporate measures to reduce sighting biases in the field and
evaluate and correct them analytically. Recommended methods for evaluating
dolphin mortality include interview surveys, carcass recovery programs, and
direct counts of fishing operations known or believed to be responsible for
dolphin deaths.
Freshwater populations of Irrawaddy dolphins can still be saved if appropriate
conservation measures are urgently implemented. To conserve these populations
it will be essential to closely involve local people in the development and
implementation of conservation plans. This will require sufficient funds and
a strong commitment from national governments and local and international
NGOs.
status and conservation of freshwater populations of irrawaddy dolphins
The idea for this volume emerged from the Workshop to Develop a Conservation
Action Plan for Freshwater Populations of Irrawaddy Dolphins held 21-26
March 2005 in Phnom Penh, Cambodia. The volume aims to publicize the
Action Plan and provide science-based justifications for urgent implementation
of recommended priority actions. The volume contains the Action Plan for the
Conservation of Freshwater Populations of Irrawaddy Dolphins, Report on the
Workshop to Develop a Conservation Action Plan for Freshwater Populations
of Irrawaddy Dolphins, and reviews of the conservation status of each of the
five freshwater populations.
The Action Plan highlights common actions needed for all five populations
and more specific actions needed for individual populations. The complexity
of devising effective solutions to address the full range of threats to freshwater
populations of Irrawaddy dolphins was beyond the scope of this workshop and
also arguably beyond the capacity to finance with available funds. Substantial
progress was made, however, on formulating some practical actions that must
be taken to prevent extinction of these populations.
A recent positive development has been the substantial research progress on
assessing the conservation status of all five freshwater populations of Irrawaddy
dolphins. This has been made possible by the dedicated work of a relatively
small group of local and international scientists and conservationists who were
mostly present at the workshop. We are proud to present in this volume reports
on the conservation status of all five freshwater populations. These reports gave
us a strong foundation for productive discussions at the workshop and development
of the Action Plan. All five reports underwent peer-review and were
edited for consistency and style, but the content remained the responsibility of
individual authors.
Between the time of the workshop and publication of this volume significant
steps have been taken to implement recommended conservation actions for
some populations. To preserve the accuracy of discussions conducted at the
workshop we decided not to revise the workshop report post-hoc but to encourage
authors of the conservation status reports on each population to include
new developments in these documents, which they have done in this volume.
in the near future, and urgent conservation measures are required for their
long-term survival. In contrast to the environmental preferences of other members
of their species, which inhabit nearshore marine waters, these animals
live far upstream in three large rivers (the Mekong in Cambodia, Lao PDR
and Vietnam, the Mahakam in Kalimantan, Indonesia, and the Ayeyarwady in
Myanmar) and in two brackish lagoons or marine appended lakes (Songkhla
in Thailand and Chilika in India, Figure 1). Balancing the resource needs of
local human communities with the survival requirements of these large, mobile,
aquatic predators is a challenging task due to their restricted distribution in
freshwater bodies which are already subjected to high levels of human use. The
irony of their endangerment is that Irrawaddy dolphins are generally regarded
positively by local people, probably due to their engaging social displays, role
in cultural folklore, and in the Ayeyarwady River participation in a cooperative
fishery with cast-net fishermen. This positive attitude enhances the potential for
working with governments and local communities to find conservation solutions
and generate local revenue through sustainable tourism.
The primary threat to most populations is incidental killing from gillnet
entanglement. In the Mekong River of Cambodia gillnet entanglement accounted
for 87% of the mean yearly, confirmed human-caused mortalities where
the cause could be identified, representing at least 5.4% of the current estimated
minimum population size. In the Mahakam River, gillnet entanglement
accounted for 66% of the mean yearly recorded mortalities and 4.0% of the
estimated population size. A particular fisheries problem threatening dolphins
in the Ayeyarwady and Mahakam rivers is electrocution from illegal electric
fishing. This non-selective fishing technique may also be causing declines in
dolphin prey.
Habitat loss and degradation are caused by water developments, gold and
coal mining operations, increasing sedimentation from dredging and shoreline
development, and large numbers of fixed fishing gears that block access to large
sections of the rivers and lagoons. The effects of these factors are difficult to
quantify but may be substantial, especially when combined with mortality from
fisheries bycatch. Chemical pollution from biocides used in shoreline aquaculture
and agriculture, mercury and cyanide used in gold mining operations,
and coal spillage from transport barges may be directly affecting the health of
status and conservation of freshwater populations of irrawaddy dolphins
certain populations and indirectly affecting them due to impacts on their prey.
Vessel harassment and collisions may also be affecting some populations, particularly
boat traffic associated with dolphin watching operations in the mouth
of Chilika Lake and possibly in the Mekong River at the Lao PDR-Cambodia
transborder and Kampi pools, while large coal transport barges in narrow
tributary habitat interfere with dolphin movements in the Mahakam River.
Strategies for mitigating bycatch include: (1) establishing core conservation
areas where gillnetting would be banned or severely restricted; (2) promoting
net attendance rules and providing training on the safe release of entangled
dolphins; (3) initiating a program to compensate fishermen for damage caused
to their nets by entangled dolphins that are safely released; (4) providing alternative
or diversified employment options for gillnet fishermen; (5) encouraging
the use of fishing gears that do not harm dolphins by altering or establishing fee
structures for fishing permits to make gillnetting more expensive while decreasing
the fees for non-destructive gears; and (6) experimenting with acoustical
deterrents and reflective nets.
Multiple-use protected areas will play a key role for conserving dolphins:
(1) in the Mekong River, at nine deep pool areas between Kratie and the Lao
PDR-Cambodia border; (2) in the Mahakam River, in 10-20 km segments in
the Kedang Pahu tributary mouth at Muara Pahu Town, the mouths of the
Kedang Kepala and Kedang Rantau tributaries, and the Pela tributary including
the southern portion of Semayang Lake; (3) in the Ayeyarwady River, river
segments between the Taping river confluence at Bhamo to the upstream end of
the second river defile at Sinkan, the downstream end of the second river defile
to Tagaung, and the downstream end of the third river defile at Kyaukmyaung
to Mingun; (4) in Songkhla Lake, in the middle portion of upper Thale Luang;
and (5) in Chilika Lake, in the area between Magamukh and the outer lake
mouth.
Research and monitoring will be needed to guide and assess the efficacy
of conservation interventions. Recommended methods for abundance estimation
include mark-recapture analysis of photo-identified individuals and direct
counts that incorporate measures to reduce sighting biases in the field and
evaluate and correct them analytically. Recommended methods for evaluating
dolphin mortality include interview surveys, carcass recovery programs, and
direct counts of fishing operations known or believed to be responsible for
dolphin deaths.
Freshwater populations of Irrawaddy dolphins can still be saved if appropriate
conservation measures are urgently implemented. To conserve these populations
it will be essential to closely involve local people in the development and
implementation of conservation plans. This will require sufficient funds and
a strong commitment from national governments and local and international
NGOs.
status and conservation of freshwater populations of irrawaddy dolphins
The idea for this volume emerged from the Workshop to Develop a Conservation
Action Plan for Freshwater Populations of Irrawaddy Dolphins held 21-26
March 2005 in Phnom Penh, Cambodia. The volume aims to publicize the
Action Plan and provide science-based justifications for urgent implementation
of recommended priority actions. The volume contains the Action Plan for the
Conservation of Freshwater Populations of Irrawaddy Dolphins, Report on the
Workshop to Develop a Conservation Action Plan for Freshwater Populations
of Irrawaddy Dolphins, and reviews of the conservation status of each of the
five freshwater populations.
The Action Plan highlights common actions needed for all five populations
and more specific actions needed for individual populations. The complexity
of devising effective solutions to address the full range of threats to freshwater
populations of Irrawaddy dolphins was beyond the scope of this workshop and
also arguably beyond the capacity to finance with available funds. Substantial
progress was made, however, on formulating some practical actions that must
be taken to prevent extinction of these populations.
A recent positive development has been the substantial research progress on
assessing the conservation status of all five freshwater populations of Irrawaddy
dolphins. This has been made possible by the dedicated work of a relatively
small group of local and international scientists and conservationists who were
mostly present at the workshop. We are proud to present in this volume reports
on the conservation status of all five freshwater populations. These reports gave
us a strong foundation for productive discussions at the workshop and development
of the Action Plan. All five reports underwent peer-review and were
edited for consistency and style, but the content remained the responsibility of
individual authors.
Between the time of the workshop and publication of this volume significant
steps have been taken to implement recommended conservation actions for
some populations. To preserve the accuracy of discussions conducted at the
workshop we decided not to revise the workshop report post-hoc but to encourage
authors of the conservation status reports on each population to include
new developments in these documents, which they have done in this volume.
Best,P.B.
Increase rates in severely depleted stocks of baleen whales Journal Article
In: ICES Journal of Marine Science, vol. 50, no. 43, pp. 169-186, 1993.
Abstract | BibTeX | Tags: abundance, Arabian Sea, baleen whales, historical whaling, population estimates, Stock identity, whaling
@article{,
title = {Increase rates in severely depleted stocks of baleen whales},
author = {Best,P.B.},
year = {1993},
date = {1993-01-01},
journal = {ICES Journal of Marine Science},
volume = {50},
number = {43},
pages = {169-186},
abstract = {The paper tries to examine the status of all known stocks of baleen whales that were depleted to an estimated 10% of their original abundance. Of 44 such stocks, 18 are classified as not feasible to monitor (including Arabian Sea humpbacks), 12 have been or are being monitored (at the time of writing), and increase rates have been demonstrated for 10 of those. The author concludes that more depleted stocks show higher rates of increase than less depleted stocks, and that most populations are reaching a size which would allow harvesting (a minimum of 60% of their pre-exploitation numbers according to the IWC). The paper points out some interesting problems with the use of historical whaling data and mark-recapture in estimating fecundity rates. It also suggests that population increases were not detected in the years immediately following protection for two reasons: 1) commercial catches were underreported and initial post-whaling population estimates were too high, 2) following population decreases, whales may condense their ranges, leaving some historical feeding or breeding sites to form concentration areas, some of which were only recently discovered.},
keywords = {abundance, Arabian Sea, baleen whales, historical whaling, population estimates, Stock identity, whaling},
pubstate = {published},
tppubtype = {article}
}
The paper tries to examine the status of all known stocks of baleen whales that were depleted to an estimated 10% of their original abundance. Of 44 such stocks, 18 are classified as not feasible to monitor (including Arabian Sea humpbacks), 12 have been or are being monitored (at the time of writing), and increase rates have been demonstrated for 10 of those. The author concludes that more depleted stocks show higher rates of increase than less depleted stocks, and that most populations are reaching a size which would allow harvesting (a minimum of 60% of their pre-exploitation numbers according to the IWC). The paper points out some interesting problems with the use of historical whaling data and mark-recapture in estimating fecundity rates. It also suggests that population increases were not detected in the years immediately following protection for two reasons: 1) commercial catches were underreported and initial post-whaling population estimates were too high, 2) following population decreases, whales may condense their ranges, leaving some historical feeding or breeding sites to form concentration areas, some of which were only recently discovered.