167

Present State and Subjects on Marine Ecosystem
Conservation in Japan
Toshio TORII
Biodiversity Policy Division, Nature Conservation Bureau,
Ministry of the Environment
1-2-2, Kasumigaseki, Chiyoda-ku, Tokyo 100-8975, Japane-mail:TOSHIO_TORII@env.go.jp

Abstract
The Ministry of the Environment has surveyed marine natural environments, such as tidal flats,
seaweed beds, coral reefs, the situation of coastlines, the status of several marine animals, etc. Howeverthese surveys are highly limited compared with surveys of land areas. And the systems of National
Parks, Nature Conservation Areas, Wildlife Protection Areas are not enough to contribute to marine ecosystem conservation. Under the circumstances that marine ecosystem conservation is one of the global
environmental key issues, though each study of fishing resources has been made progress, marine ecosystem study or marine ecosystem conservation has not been enough in Japan.
Fishing has been performed from ancient times, and fishing rights have been intricately developedin marine areas around the Japanese coast. Therefore it is very difficult to designate marine protection
areas where fishing is prohibited. The new measures that integrate marine ecosystem conservation andsustainable development are strongly expected. A community-based marine management plan is considered a realistic selection, taking into account the actual conditions of Japanese coastal fishing. The plan
will be achieved in agreement with local fishermen, residents and organizations, marine recreational
sectors, relevant official agencies and research institutions. I believe that marine ecosystem conservation
under the plan can lead to sustainable fishing that maintains and cultivates fishing resources.
Key words: marine ecosystem, marine management plan, national survey on the natural environment,
Shiretoko World Natural Heritage Site

1. Introduction
Japan is surrounded by the sea, and has tackled‘conservation and management of marine organism
resources’ on a local level, which is the theme of thisspecial edition number, for many years, in order toconserve fishing resources. Since other writers haveintroduced this matter, I would like to summarize in
my manuscript the present state of marine ecosystemconservation that the Ministry of the Environment ofJapan has so far tackled, and describe marine ecosystem conservation issues in Japan.

2. Understanding the Marine Ecosystems
Surveys of marine areas by the Ministry of the Environment are highly limited compared with surveysof land areas. This is thought to be the main reason
that the objects of administrative measures are clearlybased on land areas and relations with marine scientists are also restricted. In this situation, the main surveys of marine areas, which the Ministry of the Environment has tackled so far, are outlined as follows.
Global Environmental Research9(2)/2005: 167-174
printed in Japan

2.1 National Survey on the Natural Environment
In the days when the Environment Agency was established (1971), the marine pollution problem wasaggravating, and measures to prevent sea pollution
were mainly regulations to control of contaminantdischarge. However, it was not enough to conserve themarine ecosystem.
The Environment Agency’s grasp of the marine
ecosystem in which it was concerned systematicallystarted with the National Survey on the Natural Environment since fiscal year 1973 as a forerunner, withthe coast and the inland sea regions the main objectsof these Surveys, and this is still the tendency. An outline of the Surveys done so far is shown in Fig. 1.
2.1.1 Tidal Flats, Seaweed Beds and Coral Reefs
SurveysSurveys of tidal flats, seaweed beds and coral reefs
are carried out continuously by the National Survey
on the Natural Environment in marine areas. The survey is carried out in accordance with measures that the
Ministry of the Environment entrusts to prefectures tomonitor the situation of tidal flats, seaweed beds and©2005 AIRIES168

T. TORII

Nature Conservation Bureau, Ministry of the Environment

Fig. 1 The outline of the National Survey on the Natural Environment.

coral reefs through cooperation with local universities,
local fisheries research institutes, museums, etc.,
based on the Ministry’s operational guidelines. Eachprefecture ascertains the distribution of tidal flats, seaweed beds and coral reefs through research of existingreferences (topographical maps, aerial photos, etc.) or
field investigations. The budget for the second survey(1978-1982) was approximately 140 million yen, andthe budget for the fourth survey (1988-1992) wasapproximately 200 million yen, but the number ofstaff who were involved in this survey throughout
Japan is unknown. The Ministry of the Environment
compiled each prefecture’s results and completed bothsurveys. By the second survey, the regions of tidal flat,
seaweed bed and coral reef distribution were clear,and changes in the regions of distribution incomparison with the results of the two surveys wereclarified by the fourth survey. (The area transition of
tidal flats, seaweed beds and coral reefs based on the
results of the two surveys is shown in Table 1.) By thefifth survey (1993-1998), detailed investigation of
species compositions, etc., was conducted in some

Table 1-1 Transition of tidal flats.

(ha)

2nd Survey
4th Survey
1945
1978 Reduced % 1978
1994 Reduced %Tidal flats
82,621 53,856
34.80%
55,300 51,443
7.00%
Notes: The reason the number for 1978 in the 2nd Survey differs fromthat for the 4th Survey, is use of different investigation measures.

Table 1-2 Transition of seaweed beds.

(ha)
2nd Survey
4th Survey
1973
1978 Reduced % 1978
1994 Reduced %Tidal flats
184,776 182,727
1.10%
207,615 201,212
3.10%
Notes: The reason the number for 1978 in the 2nd Survey differs fromthat for the 4th Survey, is use of different investigation measures.

Table 1-3 Transition of coral reefs.

(ha)
4th Survey
1978
1994
Reduced %Tokyo Metro. Ogasawara Islands
461
456
1.08%
Kagoshima Pref. Amami Islands
6,060
5,951
1.80%
Okinawa Island
8,270
7,046
14.80%
Okinawa Pref.
Miyako Islands
2,027
1,957
3.45%
Yaeyama Islands 19,336 19,232
0.54%
National Survey on the Natural Environment, Ministry of theEnvironment.

Present State and Subjects on Marine Ecosystem Conservation in Japan

2.1.2 Coastline Surveys
In the Coastline Survey, classifying the coastline
into ‘natural coast,’ ‘half-natural coast,’ ‘artificial
coast’ and ‘river mouth,’ is considered fundamental
data for conservation together with determining transitions of each classified coastal length since the second
survey. Comparing the results of the fourth survey
with those of the second survey, we found artificial
coasts increased by approximately 1,340 km and natural coasts decreased by approximately 860 km (refer
to Table 2).
2.1.3 Marine Animals Surveys
In the Marine Animals Survey conducted by the
5-6th surveys, the present condition, such as distributions, was grasped for large-sized marine animals(loggerhead turtle (Caretta caretta), green turtle(Chelonia mydas), hawksbill turtle (Eretmochelys
imbricata),
finless
porpoise(Neophocaena
phocaenoides), sea otter (Enhydra lutris) and seals)

Table 2 Transition of the coastline of Japan(km)

2nd Survey
3rd Survey
4th Survey
1978
1984
1993
32,170 ( 100%) 32,472 ( 100%) 32,779 ( 100%)
Total

typical marine areas aiming at classification of tidal
flats, seaweed beds and coral reefs by biological type.

169

Natural coastline 18,967 (59.0%) 18,402 (56.7%) 18,106 (55.2%)
Half-natural
4,340 (13.5%) 4,511 (13.9%) 4,467 (13.6%)
coastline
Artificial
8,599 (26.7%) 9,295 (28.6%) 9,942 (30.3%)
coastline
River mouth
264 ( 0.8%)264 ( 0.8%)264 ( 0.8%)

National Survey on the Natural Environment, Ministry of theEnvironment.

which inhabit coastal seas. For example, for sea turtles,
the numbers landing, laying eggs, and hatching insands throughout Japan have been determined, and a
distributional map was created.
For details of each above survey, please refer to thehomepage of the Biodiversity Center, Ministry of theEnvironment (http://www.biodic.go.jp/).
2.2 Individual Surveys
Although several marine surveys were conducted
for investigating the natural environment when ex-

170

T. TORII

tending a natural park or a wildlife protection area toinclude a marine area, I would like to introduce briefly
in this section some surveys which have fixed purposes, such as preservation of certain species or conservation of important ecosystems, and which also
cover a wide area.
2.2.1 Seal Surveys
Five kinds of seals have been newly listed under
the Wildlife Protection and Regulation of Hunting
Law from 2002. The Ministry of the Environment has
surveyed the habitation of the seals (mainly spottedseal (Phoca largha), kuril harbor seal (Phoca vitulina
stejnegeri) and others), in cooperation with the
Hokkaido Prefectural Government from fiscal years
2003 to 2005, in order to study conservation andmanagement policies for seals.
2.2.2 Dugong Surveys
The dugong (Dugong dugon) inhabits marine areas
around the Okinawa main island, but the extent of its
actual habitation is not known, and it is feared to befacing extinction. Therefore, in order to study conservation policies for dugongs, the Ministry of the Environment has made visual check surveys by airplane,
investigated traces of grazing in main seaweed beds
from fiscal year 2001, and is striving to get an understanding of the extent of dugong habitation.
2.2.3 500 Important Wetlands List
The Ministry of the Environment has selected 500
important wetlands in Japan based on existing references, word from related organizations and specialists,and other sources in 2002. Shallow marine areas, suchas tidal flats, seaweed beds and coral reefs are included on this list. This list is useful in studying conservation policies or selecting additional wetlands
under the Ramsar Convention site.

3. Systems Relating to Marine Ecosystem
Conservation
Although the present systems for conserving
marine ecosystems in Japan cannot be called sufficient,
I would like to introduce below several measures
being taken for conservation of marine ecosystems.
3.1 Natural Parks
Natural Parks are designated in accordance with
the Natural Parks Law in order to conserve outstanding natural landscapes representing Japan. There
are three types: National Parks, designated and managed by the government, Quasi-National Parks, designated by the government and managed by the prefectures where they are located, and Prefectural Natural
Parks, designated and managed by the respective prefecture. National Park and Quasi-National Park areas
are usually classified as Special Protection Zones,
Marine Park Zones, Class1 – Class3 Special Zones
and Ordinary Zones, depending on the characteristicsof the natural environment and the necessity for conservation. Various kinds of development are regulated
in accordance with the zone classification from thepoint of view of conservation of the landscape.
In case of marine areas, Natural Parks, fronting
coastal parks or inland sea regions are usually designated as Ordinary Zones, from the point of view thatmarine park areas are buffer zones for land park areas.
In performing the reclamation work beyond a certain
scale, new construction of large-scale structures, etc.,
require notification to the Secretary of State for theEnvironment or the prefectural governor.
Marine Park Zones are designated at coral reefs orseaweed beds with especially beautiful scenery among
National Parks or Quasi-National Parks. In Marine
Park Zones, various development work and collecting
or damaging specific animals and plants are prohibited.
As of April 2005, a total of 64 zones, comprising
2,664 ha had been designated as Marine Park Zones in
National Parks and Quasi-National Parks.
3.2 Nature Conservation Areas
Nature Conservation Areas are designated in accordance with the Nature Conservation Law in order
to conserve areas almost untouched by human beingsor having outstanding nature. As of April 2005, fiveWilderness Areas and ten Nature Conservation Areas
had been designated. Sakiyama Bay Nature Conservation Area (128 ha), located in Okinawa Prefecture, isthe only marine Nature Conservation Area in Japan
aimed at conservation of coral reefs. In this area, various development work and collecting or damaging
specific animals and plants are prohibited.
3.3 Wildlife Protection Areas
Wildlife Protection Areas are designated in accordance with the Wildlife Protection and Regulation of
Hunting Law in order to conserve wildlife habitat.
There are two types of Wildlife Protection Areas: one
designated by the Secretary of State for the Environment and the other designated by the prefectural
governor. Capture of wildlife in Wildlife Protection
Areas and development work, such as constructing
structures, reclaiming aquatic areas and cutting treesin Special Protection Zones, are regulated. It is possible for Wildlife Protection Areas and Special Protection Zones to be designated in marine areas. As of
April 2005, there were 60 National Wildlife Protection
Areas (totalling 518,153 ha) in Japan and ten areas(totalling 22,346 ha) designated which included
marine areas and six of these had Special Protection
Zones.
3.4 Red Data Book
In contrast with the above measures (1) – (3),which involve designation of conservation areas, theRed Data Book (RDB) clarifies the endangered species status of wild fauna and flora in Japan and explains conditions of their habitation, in order to avoid
their extinction and to promote understanding of theirsituation in general. In Japan, the Ministry of theEnvironment has compiled an RDB, including wildPresent State and Subjects on Marine Ecosystem Conservation in Japanfauna and flora of inland areas and some marine mammals inhabiting coastal marine areas. The Fisheries
Agency also compiled an RDB covering the sea lessthan 200-nautical miles from shore and inland water
regions (note: the formal name of the Fisheries
Agency’s RDB is The Data Book on the Endangered
Aquatic Wildlife in Japan). For your reference, thenumbers of species by category classified in the
Fisheries Agency’s RDB are listed in Table 3.
3.5 Others
There are several laws described below whose purposes are not directly related to marine ecosystemconservation and whose jurisdiction does not belong
to the Ministry of the Environment.
3.5.1 Cultural Properties Protection Law
Among the natural monuments or special naturalmonuments designated in accordance with the Cultural Properties Protection Law, there are two typemonuments included from the viewpoint of the scientific importance. The first type includes habitat/
location of important animals and plants, and thesecond type includes zones containing characteristic
geological features or minerals. An example of thefirst type is the marine area habitat of the finless porpoise (Neophocaena phocaenoides) (Takehara-shi,
Hiroshima Prefecture), and of the second type,
Tojinbo just off a characteristic coast (Mikuni-cho,Fukui Prefecture). In natural monument zones, permission is required for human activities which couldchange the present condition of the zone, such as various kinds of development.
3.5.2 Law for Conservation of Aquatic
Resources and the Fishing Law
Based on these laws, the Fisheries Agency or prefectural government can regulate capture of animals orplants, or designate marine areas which are importantfor spawning and growth of particular fishery animals
from the viewpoint of maintenance and cultivation ofmarine resources. Based on the Law for Conservationof Aquatic Resources, as of April 2005, there were six
marine areas in which the capture of the respective
marine animal (olive ridley (Lepidochelys olivacea),
leatherback turtle (Dermochelys coriacea), blue whale

171(Balaenoptera musculus musculus), bowhead whale(Balaena mysticetus), finless porpoise (Neophocaena
phocaenoides), dugong (Dugong dugon)) is regulated.
In addition, capture restrictions are individually prepared by Fishery Coordination Committees of eachmarine region, defined according to the Fishing Law.

4. Marine Ecosystem Conservation Issues
4.1 Understanding the Marine Ecosystems
A summary of the current understanding and conservation of marine ecosystems was given above,
focusing on the measures by the Ministry of the Environment. Each survey, however, is limited to somespecies or some regions. Therefore the information is
fragmentary, and cannot explain the structure of complicated marine ecosystems. The general grasp ofmarine ecosystems is vague, including the relationshipbetween marine and land areas, and it is in a trial anderror stage, using the scientific survey techniques anddevelopment of monitoring benchmarks for marine
ecosystems.
Thus, while data on marine ecosystems are extremely limited, Fish Catch Statistics are considered tobe effective as a barometer for marine ecosystems.
Although these statistics include only commercially
useful species as fishing resources and the data are
influenced by the amount of fishing efforts and otherfactors, the accumulation of many years of statistics
can provide important information on the situation in
the marine ecosystem. Moreover, if an analysis basedon the experiences of fishermen who are usually incontact with the ocean is added, it may be very effective to grasp the situation of the distribution, quantityand appearing time of each marine life other than fishery species. However, analyses based on experiences
as above are usually explained with such remarks as,‘Their number is on the decrease compared withancient times,’ and cannot be called scientific data.
Therefore, it is necessary to collect and accumulate
information on marine changes, such as the distribution, quantity and appearing time of marine life, seawater temperature, ocean currents, etc. through thecooperation with fishermen as scientific data.

Table 3 The number of species by category classified in the Fisheries Agency’s RDB.*
evaluated number(species, subspecies,
subpopulation)80( 77)
86( 67)65( 64)34( 31)57( 44)38( 37)31( 30)25( 25)

Vulnerable

Near
Threatened

Decreasing

Decreasing
Trend

4
7
15
5
7
14
3
10

8
8
13
9
4
4
4
2

18
14
16
12
16
14
8
8

26
26
12
2
8
0
8
1

14
14
6
4
3
4
5
2

10
17
3
2
19
2
3
2

0

0

2

6

5

2

1
66

0
52

0
108

0
89

0
57

0
60

Endangered

Molluscs
Marine fish
Fresh water fish
Amphibians and Reptiles
Aquatic mammals
Aquatic plants
Xiphosura and Crustacea
Water birds
Sponges, Coelentera and15( 14)Echinoderms
Aquatic insects
1( 1)
Total
432(390)* The Data Book on the Endangered Aquatic Wildlife in Japan.

Normal172

T. TORII

4.2 Conservation of Marine Ecosystems
Fishing has been done for many years, and fishingrights have developed intricately in marine areas near
the Japanese coast. Coastal fishing methods have notbeen used for all marine products, but sustainable
techniques have been chosen by designing fishing
implements to catch useful marine products selectively.
Because of these social and historical backgrounds, aMarine Protection Area (MPA) system that prohibits
the capture of all marine life has not come into existence in Japan. The structures of conservation systems
introduced above have not been intended to eliminate
fishing fundamentally.
Taking into consideration appropriate zoning
measures for marine ecosystem conservation in Japan,
it is difficult to designate MPAs widely like so-called‘sanctuaries’ which prohibit capture of all marine life.
Rather it is important to formulate a community baseda marine management plan which includes not only
fishing but recreation, such as recreational fishing,marine animal watching, etc., through cooperation
with the local stakeholders, such as administrations,scientists and fishery organizations. A marine management plan will be considered a realistic selection if ittakes into account the actual conditions of Japanese
coastal fishing, and I believe that marine ecosystemconservation under such a plan can lead sustainablefishing that maintains and cultivates fishing resources.
The marine ecosystem is influenced by various
factors, such as climate, ocean currents and interaction
with land ecosystems. We may therefore expect
hypothesis about changes in monitoring indices to bemade and evaluations for remedial measures performed while many indefinite elements remain. In
order to reduce this uncertainty and to achieve suitableecosystem management, the establishment of a monitoring system from a mid- to long-term viewpoint is
crucial. Preparation of various kinds supports measures to back up the system and an adaptive management based on the monitoring results are also important issues. Furthermore, it will be desirable to develop a method of evaluating the economic effect on
the local community brought on by the implementation of the marine management plan, in considerationof raising motivation for the plan, not only in the area
concerned but also in other areas.
[Example of measures in Shiretoko]
The understanding and conservation of marine
ecosystems using the above measures requires cooperation with related local governing bodies, fishermen,
fishery organizations, etc., and these are difficult toachieve if a certain level of motivation cannot be created. I would like to introduce briefly below the example of one measure soon to be taken in Shiretoko.
In January 2004 the Shiretoko Peninsula wasnominated by the Government of Japan as a World
Natural Heritage Site based on the World Heritage
Convention. The nominated site includes a marine

area for the first time as a natural heritage site in Japan.
In the process of the examination for registration, theIUCN pointed out the need for the Government ofJapan to extend the nominated marine site and expedite a Marine Management Plan (MMP) as well as
strengthen the provisions within this plan so as to ensure the protection of marine species. The Government of Japan has answered that the nominated site
will be extended from the current area of within 1 kmof the coastline to the area within 3 km of the coastline, and the time frame for formulation of the MMP
will be reduced to three years or less (refer to Fig. 2).
The MMP will identify proper and reliablemeasures for the conservation and management ofmarine life such as walleye pollack (Theragra
chalcogramma) and other fish that are importantfisheries resources and that support the food chain
and material cycle in the marine ecosystem, as wellas marine mammals (Steller sea lion (Eumetopias
jubatus) and seals) and sea eagles (Steller’s sea eagle(Haliaeetus pelagicus) and the white-tailed eagle(Haliaeetus albicilla)), by specifying necessary regulations in detail with regard to the following topics.
(1) Research and monitoring
The MMP will identify the targets, content, methods, priorities and other items relating to the research
and monitoring activities. These items will be reviewed and adapted in accordance with scientificverification of the results of research and monitoring.
(2) Strategies to maintain fisheries resources forcontinuing sustainable fisheries and measuresfor conservation and management of marine lifeand ecosystems
The MMP will contain the following items, including methods to reflect the findings of future research
and monitoring.
・ With regard to fisheries resources, existing fishery
restrictions and voluntary restrictions enforced by
local fishermen and fishery organizations will beincorporated into the MMP as community-basedmarine resource management initiatives. Furthermore, the MMP will identify strategies and measures necessary for sustainable use of fisheries resources, and conservation and management ofmarine life and ecosystems, based on scientificverification of the research and monitoring findings and with the agreement of local fishermen,
fisheries organizations and other stakeholders.
・ With regard to marine mammals, the MMP will
identify proper management strategies for Steller
sea lion and seals in the marine area surrounding
Shiretoko based on a survey currently being conducted on the visitation patterns, feeding behavior
and food habits of these marine mammals, as well
as a fact-finding survey on the impacts regarding
fisheries, and with the agreement of local fishermen, fisheries organization and other stakeholders.
・ With regard to sea eagles, the MMP will identify
conservation and management measures including

Present State and Subjects on Marine Ecosystem Conservation in Japan

173

Geographical locationof Shiretoko
Latitude:
44°07′23″ North
Longitude
145°09′36″ East

Fig. 2 Area nominated for the Shiretoko World Natural Heritage Site.

the protection of wintering sites and breeding sites,in conformity with the ‘Program for the Rehabilitation of Natural Habitats and Maintenance of Viable
Populations’ targeting Steller’s sea eagle and thewhite-tailed eagle currently under development.
(3) Strategies to promote proper use of the nominated site for marine recreation
・ The MMP will identify strategies to promote theproper use of the nominated site for marine recreation, which is forecasted to increase should the site
be inscribed on the World Heritage list, based on
the understanding of the current status of marine
recreation activities such as kayaking in the nominated site and usage of the site’s marine area forleisure fishing and powerboating.

・ These strategies will include those to prevent andreduce the impact of marine recreation activities on
seabirds, marine mammals and other marine life.
(4) Administrative structure
・ The MMP will clarify the sharing of responsibility
and the way of coordination among local residents
and organizations, relevant governmental agencies
and research institutions.
In formulating the MMP, the Marine Area Working
Group which was established in March 2005 under the
Shiretoko World Heritage Nominated Site ScientificCouncil will compile advice necessary to prepare a
draft of an MMP within a period of one year. The
MMP will include current fishery restrictions and thecommunity-based voluntary restrictions enforced by174

T. TORII

fishermen and fisheries organizations. Subsequently,
relevant governmental agencies will, based on thisadvice, finalize the MMP on the premise of existing
fisheries rules in consultation with relevant localorganizations, such as fisheries, and research institutions, such as universities and fisheries research institutes. During that process, the governmental agencies
will obtain advice from the Shiretoko World Heritage
Nominated Site Scientific Council and also formulate
a consensus by gathering opinions through public participation procedures, such as explanatory meetings
for local fisheries organizations and stakeholders, andother opinion-submitting procedures.

5. Conclusion
The systems of Natural Parks, Nature Conservation
Areas and Wildlife Protection Areas have been built
from the measures focused on some beautiful sceneryor specific species, and those are not enough to conserve the marine ecosystem sufficiently. In these days
the new measures that integrate marine ecosystemconservation and sustainable development are strongly
expected.
The marine ecosystem is related with the land ecosystem and economic activities complexly, so there
are many stakeholders to conserve the marine ecosystem. Therefore prohibitive or hardly regulative measures are difficult to achieve the agreement. A community-based marine management plan is one of the useful and realistic measures to conserve the marine ecosystem. Of course scientific study of marine ecosystem other than fishing resources should be carried out
widely and deeply to clarify the base for reaching a
consensus with many stakeholders. The marine management plan will be achieved in agreement with local
fishermen, residents and organizations, marine recreational sectors, relevant official agencies and research
institutions. The plan includes the contents such as
examples of Shiretoko and clarifies the sharing of responsibility and the way of coordination among theabove stakeholders in order to contribute the local
development through the marine ecosystem conservation. I believe that marine ecosystem conservation
under the plan can lead to sustainable fishing thatmaintains and cultivates fishing resources. It is important to establish a Japanese system of marine ecosystem conservation, through repeated trial and error.
References
Fisheries Agency (1998) The Data Book on the Endangered
Aquatic Wildlife in Japan, Japan Fisheries Resources Conservation Association, Tokyo. (in Japanese)
Ministry of the Environment (2002) The National Biodiversity Strategy of Japan. (in Japanese)
Nature Conservation Bureau, Environment Agency (1993) The
Outline of the National Survey on the Natural Environment.
(pamphlet in English)
Nature Conservation Bureau, Environment Agency (1994) The
Report of the Coastline Survey in the 4th National Survey on
the Natural Environment. (in Japanese)
Nature Conservation Bureau, Environment Agency (1998) The
Report of the Marine Animals Survey in the 5th National
Survey on the Natural Environment. (in Japanese)
Nature Conservation Bureau, Environment Agency (1994) The
Report of the Marine Biotic Environment Survey in the 4th
National Survey on the Natural Environment. (in Japanese)
Nature Conservation Bureau, Environment Agency (2002)
Threatened Wildlife of Japan – Red Data Book 2nd ed. –Vol.1, Mammals. (in Japanese)
Nature Conservation Bureau, Ministry of the Environment(2001) For Coexistence of People and Nature. (pamphlet inEnglish)Nature Conservation Bureau, Ministry of the Environment(2002) The 500 Important Wetlands in Japan. (in Japanese)
Nature Conservation Bureau, Ministry of the Environment(2005) The Letter to UNESCO World Heritage Centre on
Shiretoko World Natural Heritage Nominated Site. (homepage of Ministry of the Environment in English)
Nature Conservation Bureau, Ministry of the Environment(2004) The Report of the Habitation Situation of Seals in
Hokkaido. (in Japanese)
Wildlife Division, Nature Conservation Bureau, Ministry of theEnvironment (2002) The Report of the Methods on Wide
Range Survey of Dugongs. (in Japanese)(Received 16 May 2005, Accepted 1 July 2005)