1                                            Technical Note on Hydrotest

1.1                                      Background

CCI 250, a corrosion inhibitor, is proposed for use during hydrotesting of the proposed gas pipeline between the Proposed LNG terminal on South Soko Island and Black Point.  Hydrotest waters which will contain CCI250 would be disposed by discharge into the sea.

The UK-based manufacturer was required to assess CCI 250’s environmental effects. “The test results were submitted to CEFAS (Centre for Environment, Fisheries & Agricultural Science – an Executive Agency for the UK Government) and was accepted onto the List for Approved Products suitable for use by the North Sea Oil and Gas Industry. The Product Based Hazard Quotient given as 2.40E-02, one of the the ‘least environmentally hazardous’ classifications.  Subject to normal government restrictions, CCI 250 can therefore be discharged into the marine environment.”

Under the European offshore notification scheme, the use of CCI 250 is accepted by countries of the European Community including Belgium, Denmark, Finland, France, Germany, Iceland, Ireland, the Netherlands, Norway, Portugal, Spain, Sweden, United Kingdom, Luxembourg and Switerland, all of which are signatories of the OSPAR agreement for the protection of the marine environment. Furthermore, according to the manufacturer, the use of CCI 250 is approved in countries such as Russia, Singapore, Korea, USA and UAE.  According to the manufacturer, there are no instances, where use of CCI 250 has been refused on environmental grounds.

The tests on CCI 250 were conducted to determine biodegradability, bioaccumulation and toxicity.  These demonstrated CCI 250 has good biodegradability and low bioaccumulation. Toxicity of CCI 250 was based on tests using:

 

·       Fish – Juvenile turbot Scophthalmus maximus (synonymous with Psetta maxima)

·       Sediment reworkers - amphipod Corophium volutator

·       Marine algae – the diatom Skeletonema costatum; and,

·       Marine invertebrates – the copepod Acartia tonsa

The results of the toxicity tests were summarised as follows ([1]) :

·       Fish (juvenile Turbot Scophthalmus maximus): tested in accordance with OECD Guideline 203 to determine a 96 hour LC50 value (the Lowest Concentration to kill 50% of the fish during a 96 hour test).  All the fish survived the test, so the LC50 value was determined to be >1000.0 mg per litre.  That is, CCI 250 was determined to be relatively harmeless to fish.

·       Sediment reworkers (amphipod Corophium volutator): test method based on PARCOM (Paris Commision Protocol) 1995, a 240 hour test.  The LC50 was found to be 7024.8 mg kg-1 dry weight of sediment, with the NOEC (No Observable Effect Concentration) found to be less than 5623.4 mg kg-1.  These results showed CCI 250 to have a low toxicity to sediment reworkers.

·       Marine algae (Skeletonema costatum): tested in accordance with ISO?DIS 10253 over 72 hours.  The EC50 value (Effective Concentration, the amount of material which inhibited algal growth rate by 50% over the test period) was calculated to be 23.2 mg l-1.  The NOEC was determined to be 17.8 mg l-1.  This showed CCI 250 was moderately toxic to marine algae.

·       Marine Invertebrates (copepod Acartia tonsa): tested according to the draft method ISO 14669:1999(E) over 48 hours. The EC50 value (Effective Concentration, the amount of material which immobilised 50% of the copepods over the test period) was calculated to be 260.1 mg l-1.  This test showed CCI 250 had a relatively low toxicity level to marine invertebrates.

1.2                                      Purpose of this Note

This note discusses the applicability of these toxicity test findings in the Hong Kong environment in terms of suitability of test organisms to reflect effects on Hong Kong’s marine ecology.

1.3                                      Relevance of Test Organisms

1.3.1                                Scophthalmus maximus

The flounder Scophthalmus maximus is a commercially important temperate predatory benthic species, living on sandy, muddy, rocky and mixed bottom habitat, and particularly favours brackish areas. Its natural range is along European coast including the Baltic and North Sea and it also occurs in the warmer Mediterranean and Black Seas as well as off Northwest Africa ([2]). In China, it is an important species used in aquaculture operations.

Although, this fish does not naturally occur in Hong Kong, there are a diversity of related species which occupy similar ecological niches, have similar functional adaptations and comparable ecologies and habitat preferences.  To date 28 species of flounder mostly warm water species, are recorded from Hong Kong waters, with some species having ranges into temperate areas off Japan and the Yellow Sea ([3]) .  As with other marine groups, the flounders and other ichthyofauna of Hong Kong are comprised representatives from both temperate and warmer water regions.  This is because Hong Kong lies at the junction of the temperate Palaearctic Japonic zoogeographical region and the tropical Oriental region. Sea surface temperatures in Hong Kong range down to 12°C in the dry season, and as high as 32°C in the wet season. 

Based on this information, it is considered there is no reason to suggest that Scophthalmus maximus is not a suitable test organism for reflecting toxicity effects in the Hong Kong marine environment.  

1.3.2                                Corophium volutator

The amphipod Corophium volutator (sometimes called a “mud-shrimp” or “scud”) is a burrowing benthic animal which inhabits muddy bottom habitat. It is deposit and filter feeder that sifts the organic material (such as micro-algae and bacteria) from mud particles.  In terms of its distribution, it is predominantly a European species, occurring from Scandinavia to the warmer waters of the Mediterranean.

Although Corophium volutator is not found locally, there are 10 species in the Family Corophiidae in Hong Kong including 4 in the genus Corophium ([4]).  These species have comparable habits and ecologies to Corophium volutator. Among these locally occurring Corophium, are species which have distributions ranging into temperate regions such as Japan. As noted previously, in Hong Kong, marine organisms including the amphipods comprise a mix of temperate and tropical species.

Given that there are highly related Corophium species in Hong Kong which have representatives from temperate regions, it is considered there is no reason to suggest that Corophium volutator is not a suitable test organism for reflecting toxicity effects in the Hong Kong marine environment.

1.3.3                                Skeletonema costatum

The diatom Skeletonema costatum is a cosmopolitan algal species found in coastal waters of all the world’s oceans.  It thrives in Hong Kong and is a common species recorded in phytoplankton samples locally.

Given that this species occurs locally, there is no reason to suggest that Skeletonema costatum is not a suitable test organism for reflecting toxicity effects in the Hong Kong marine environment.

1.3.4                                Acartia tonsa

Acartia tonsa has a widespread global distribution which includes tropical waters.  It has been recorded from the Indian Ocean, off the Malay Archipelago, the Caribbean, and along the Atlantic and Pacific coasts of the North and South America.

Although, it appears Arcatia tonsa has not been recorded from Hong Kong waters, other Arcatia species have been identified locally.

Based on this information, it is considered there is no reason to suggest that Arcatia tonsa is not a suitable test organism for reflecting toxicity effects in the Hong Kong marine environment.  

 

 



([1]) Extracted from CEFAS Summary Sheet

([2]) www.fishbase.org

([3]) www.hk-fish.net

([4]) City U (2002) Marine Benthic Studies in Hong Kong. Submitted to AFCD.