Coliform contamination of indigenous clam,Batissa violacea (Lamarck, 1818) (Bivalvia)
in Cagayan River, Philippines:
Implications to human health safety• Recent infectious disease outbreaks caused by theconsumption of bivalves contaminated withpathogenic viruses and bacteria has been recognized
as a worldwide public health problem (Carlos et al.,2007).
• Bivalves are regarded as potentially hazardous foodbecause of their inherent tendency to bioaccumulate
toxic metal through filter feeding (Hatha et al., 2005;
Adjei‐Boateng et al., 2009).

• Land Use Change: growing urban development in region
02 (Rimando, 2003)• 3 cities (Tuguegarao, Santiago and Cauyan)• 2007 ‐ 3.05 M (114 persons/km2)• 2020 ‐ 3.15 M 2020 (Cagayan Valley RegionalDevelopment Plan 2011‐2016).

•Previous incident of pollution (Coliform Bacteria) in theCagayan River waters due to discharge of untreated wastes byresidences and buildings (http://www.dpwh.gov.ph).
•Limited available studies on coliform concentration test offishes and mollusks from Cagayan River.

Determine the levels of total coliform and E. coliformcontamination in the flesh of B. violacea and its riverinewater .

Freezing/Icing

River water samples

DOST Region 02 Laboratory

Table 1. Comparison of coliform count (T.C and E. coli) of harvesting areas of B.
violacea to different standard acceptable coliform levels
STATION/COUNTRY/INSTITUTION
Station 1
Station 2
Station 3
Station 4
Station 5
Station 6
Mean station
DENR Administrative Order (DAO),1990
DENR Administrative Order (DAO),
2008
European Union (EU)
United States (US)United Nations Environment Program(UNEP)
World Health Organization (WHO)
Wider Caribbean Region (WCR)
Iceland

TOTAL COLIFORMCOUNT (MPN/100 ML)
> 8.0
> 8.0
> 8.0> 8.0
> 8.0
> 8.0
> 8.0

ESCHERICHIA COLI
COUNT (MPN/100 ML)
> 8.0
> 8.0
> 8.0
> 8.0
> 8.0
> 8.0
> 8.0

5000

‐

‐

200*

‐

14 and below*
14 and below*‐

10 and below for 80% of samples*‐‐‐

10 and below for 80% of samples*43*
14 and below*

Source: Modified from Owili, 2003
Note: * = Fecal coliform
Station 1=Aguiguican, Gattaran; Station 2=Sta. Maria, Lallo; Station 3=San Lorenzo, Lallo; Station 4=Catayauan, Lallo; Station 5=Tucalana, Lallo; Station 6=Jurisdiction,Camalaniugan.

Table 2. Comparison of coliform count (T.C and E. coli) of B. violacea flesh tissues todifferent standard acceptable coliform levels.

B. VIOLACEA INCAGAYANRIVERPHILIPPINEFDACIRCULAR
NO. 2013‐010

Total Coliform count(MPN/g)> 1100 MPN/g

Escherichia coli count(MPN/g)> 1100 MPN/g

COLIFORMEUROPEAN UNION (EU) CATEGORY (a)ENVIRONMENT CANADA(EC) (b)

A

B

C‐‐‐‐

‐

16 MPN/ g<230
MPN/100 g<4,600
MPN/100 g<46,000
MPN/100 g

230
MPN/100 g

Note:•(a)= Criteria for the classification of live bivalve molluscs harvesting areas under Regulation (EC) No. 854/2004, (EC) No. 2074/2005, (EC)No. 1021/2008 and (through cross‐reference) Regulation (EC) No. 853/2004 and Commission Regulation (EC) No. 2073/2005 on
microbiological criteria for foodstuffs (Carlos et al., 2011).
•(b)= Oyster meat samples (Sonier et al., 2006)

•High concentration of TC and E. coli (>1,100 MPN/g) in themeat of the B. violacea could be explained by the underlying
sediments of the bivalve.
•The B. violacea could possibly ingests the bacteria since it isa filter feeder bivalve that burrows to the sediment at aconsiderable depth (Thangavelu et al., 2011).

•Cagayan River Basin to put control mechanisms in place toprevent the pollution in the river waters and bacterial
contamination in the B. violacea and other fisheryresources of the river.
•Depuration of the clam in clean running water to reducethe bacterial load to acceptable levels .
•Thorough cooking of the clam before consumption.

• IEC campaign on the importance of depuration as ameans of decontaminating the clams should beincorporated into the general shellfish fishery
management in the region.
• A study to test the potentially pathogenic contamination
to hazardous levels by B. violacea sold in the wet markets
in the region.
• A study to analyse possible contamination of B. violacea
in the river and wet markets to heavy metals.

Journal ofEnvironmental
Science andManagement(JESAM)