Biological impacts caused by the release of the imported ......ecosystem function. Annually, NIS cause environmental damage and economic losses in excess of US $137 billion in the

Tidal flat in Japan

Sea grass bed in Japan

Biological impacts caused by the release of the imported manila clam,

Ruditapes philippinarum, in Japan

Naoaki TEZUKA and Masami HAMAGUCHI(FEIS)

P-1

0

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1819

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year

Am

ount

of t

he c

lam

（met

ric

ton） t he import ed clam

Landings in J apan

Changes in landings and amount of the imported clam in Japan

P-2

Import origin of the clam

0 5,000 10,000 15,000 20,000 25,000 30,000

Amount of the imported clam(ton)

North Korea

China

Korea

others 2005

P-3

Biological impacts caused by the imported manila clam

• Is the imported clam genetically identical to the native clam ?

• Does nonindigenous species (NIS) introduce with the imported clam ?

• Does pathogens introduce with the imported clam ?

P-4

Construction of the mitochondrial DNA of the clam

Total length was 22.7Kbp. The mitochondrial DNA of manila clam was longer than human !

unknown NC- 3CO2 t - RNACyt B 16SrRNAND4 t - RNAATPFO ND3ND5 t - RNAND6 t - RNACO3 12SrRNACO1 t - RNAND1 ND2NC- 1 ND4LNC- 2 t - RNA

P-5

0.01

Kore

a

China

Yosh

itomi

1.00

0.81

Hamf

un

Won

san

1.00

Miya

jima

Akke

shiVene

rupis

1.00

Phylogenetic relationship among 8 populations collected from China, Korea and Japan.

0.01China form-1

China form-2

Eastern KoreaEastern Korea

Southern Korea

Hiroshima Japan

HokkaidoJapan

HokkaidoJapan

P-6

Rapid identification of genetic formof the clam by PCR and real-time PCR

Preparation

Of DNA

PCR-RFLP

Real-time PCR

Genetic form Japan-southern Korea

国産中国産

genetic form China

M A B C M（A）genetic form China-1、（B）genetic form China-2、（C）genetic form Japan-southern Korea

React to genetic form Japan-southern Korea form only!P-7

Genetic form of the clam collected from China to Japan, revealed by the rapid identification method.

Japan-Korea forms

Chinese forms

coexistence

P-8

150bp

160bp

170bp

Yasuda et al. Molecular Ecology Notes (2006)

Microsatellite marker of the clam

1 2 3 4 5 6 7 8 9 1011 121314 151617181920212223Individuals

P-9





P-10

What is NIS?Nonindigenous species (NIS): a species

introduced to areas beyond its native range by human activity

Many human activities, such as agriculture, aquaculture, recreation and transportation, promote both the intentional and accidental spread of species across their natural dispersal barriers. Although most organisms die in transit, or soon after release, those that persist can have grave effects on human health, devastating economic impacts, and can threaten native biodiversity and ecosystem function. Annually, NIS cause environmental damage and economic losses in excess of US $137 billion in the USA alone.

Invasion of marine NIS is wide spread phenomenon in the world. Marine organisms have been moved around the world accidentally or intentionally. Aquaculture is now considered one of the major gateways for introduction of Marine NIS.

P-11

Transporting route from china to Miyagi Prefecture

Survey of NIS with the imported clam

Prof. Okoshi surveyed NIS with imported manila clam from China to Miyagi Prefecture, Japan.

Ship freighted with clams and NIS just before relaese

Sacks filled with the clam imported from China

from Okoshi, 2005

P-12

a

c

b

e

dg

f

NIS collected from the clam sacks. a, Euspira fortunei; b, Glossaulax didyma; c, Glossaulax reiniana;

d, Varichinassa varicifera; e, Trigonostoma scalariformis.; f, Meretrix petechialis; g, Crassostrea gigas.

P-13

Mangoku-ura inlet

Matsushima Bay

Obitsu RiverLake Hamana

Kushida River

Nakatsu

Ariake Sound

Matsukawa-ura Inlet

Miyako

Torinoumi inlet

Mikawa Bay

Distribution of the mollusk-eating snail Euspira fortunei in Japanese waters.

No found

Native habitat

P-14





P-15

Perkinsus spp. in the imported clam

Histological observation

of gill

Hamaguchi et al,(1999) reported high prevalence rate of perkinsus protozoan in imported clam.

P-16

Mangoku-ura inlet

Matsushima Bay

Obitsu RiverLake Hamana

Kushida River

Nakatsu

Ariake Sound

Matsukawa-ura InletTorinoumi inlet

Mikawa Bay

No found

Infection area of Perkinsusprotozoan

Distribution of the Perkinus protozoan, which is parasite of the clam, in Japanese waters.P-17

Hiroshima

the clam production areas （over 1000

tons)

01020

3040506070

8090

100

Recreat ional shellfishgathering grounds

Fishing ground of the clam no fishing ground

Prev

alen

ceof

Perk

insu

spr

otoz

oan(

%)Prevalence of Perkinsus protozoan in recreational shellfish gathering grounds,

fishing grounds of the clam and undisturbed or no fishing grounds

**

release of the imported clam by fisherman’s cooperative

P-18

0.0010.0020.0030.0040.0050.0060.0070.0080.0090.00

100.00

0 7 14 21 28 35 42 49 56 63 70 77 84 91

Days after release

Prev

alen

ce o

f Per

kins

uspr

otoz

oan（

％）

St .1St .2

Does Perkinsus protozoan infect in fishing ground in Japan ?

Waterborne infection in Japanese water !

We released the non-infected clam to the aquaculture ground of the imported clam・・・

P-19



No it is not!

The naive clam is genetically different from the almost imported clam.

So the imported clam itself is also NIS.P-20

Biological impacts caused by the imported manila clam in Japan


Yes it is !Euspira fortunei is becoming a new, strong

predator of the native clam stocks in Japan. The effect of NIS with the imported clam

on preexisting population is also important problem to be solved.

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Yes or No

But, We need to attention to

NIS problems・・・

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“Resource enhancing project of the native clam”

is necessary, and it is starting now in Japan.


• In the case of the clam, imported clam can have negative effect to the clam production in Japan.

P-22

Thank you !

Dr. Hamaguchi will correspond.E-mail: [email protected]

Biological impacts caused by the release of the imported ......ecosystem function. Annually, NIS cause environmental damage and economic losses in excess of US $137 billion in the

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