Derek Ellis

Widespread neogastropod imposex: A biological indicator of global TBT contamination?

Abstract Imposex (male genitalia imposed on females) in shoreline whelks and other Neogastropod molluscs is reported here from S.E. Asia (Singapore, Malyasia and Indonesia). In Singapore imposex occurred at all sites where females were available. In remote Ambon Bay, Indonesia, imposex also occurred widely, and was particularly severe in two harbours for high seas and inter-island vessels. There was a low incidence of imposex near Port Dickson, a small port in Malaysia. As whelk imposex occurs widely in North Atlantic and Pacific Oceans, we conclude that it is now global not just regionally localized. From the association of Neogastropod imposex with tributyltin (TBT) contamination derived from boat and ship anti-fouling paints, it follows that TBT contamination and its human consequences should be considered a contemporary global threat. We present here an imposex survey protocol for Neogastropod species in general. This should facilitate testing in new regions with new species, and indicate where chemical measures for TBT contamination are needed.

Widespread neogastropod imposex in the Northeast Pacific: Implications for TBT contamination surveys

Abstract Imposex (male genitalia imposed on females) occurred in shoreline whelks throughout the Straits of Georgia, Puget Sound, the Straits of Juan de Fuca, and exposed west coasts of this region of the Northeast Pacific Ocean. Such neogastropod imposex indicates contamination by TBT-based boat and ship anti-fouling paints. Thirty-eight sites in total have been sampled quantitatively, with all six species now reported being affected. All female whelks collected within 1 km of marinas and harbours showed imposex, with lesser levels under lower boat traffic conditions. On the outer coast of the State of Washington, USA, and Vancouver Island, Canada, even in remote National Parks, imposex occurred. At only two sites sampled were there unaffected populations. If tributyltin contamination is the sole cause of neogastropod imposex, then the entire inside waters of the Straits of Georgia, the Straits of Juan de Fuca and Puget Sound are affected by TBT.

Submarine tailings disposal (STD) for mines: An introduction

The basic submarine tailings disposal (STD) design consists of a tailings line to a deaeration / mixing chamber, with a seawater intake line, and discharge to location and depth allowing gravity flow of a coherent density current to final sedimentation area. Such STD systems can place mine tailings at locations and depths constraining environmental impact to (1) restricted areas of seabed, and (2) deep water turbidity. At some coastal and island locations, STD provides a tailings disposal option that can haue less cumulative environmental impact than the alternatives of disposal to pit, surface (dam impoundment), or river or lake. There needs to be minimal risk of tailing suspension, or resuspension, and upwelling to surface waters. The potential for these risks can now be calculated by modeling procedures. An STD system has been operating at Island Copper Mine, Canada, since 1971, with only minor environmental and technical problems involving irregular resuspension events, maintenance of the system, and ...

Deep water STD at the Misima gold and silver mine, Papua, New Guinea

>The Misima Mine is the pioneer of deep‐water submarine tailings disposal (STD) and discharges at 112‐m depth, well below the zone of major biological productivity (euphotic zone), onto a steep seafloor slope that leads directly to a deep ocean basin. The system discharges approximately 18,000 tonnes of tailings solids per day and has a mix tank with seawater intake from 82‐m depth. Prior to discharge, each tailings part is diluted with approximately seven parts of seawater. Two validation surveys have shown that the system complies with regulatory conditions and meets ambient standards for contaminants well within a submerged mixing zone that extends to 1200‐m radius from the mix tank location. Video records obtained by remotely operated vehicle (ROV) show the tailings slurry descending the steep slope as a coherent bottom‐attached density current to at least the limit of the ROV tether at 160‐m depth. Geophysical survey and ocean floor sediment sampling has confirmed that accumulation of tailings solids...

Importance of geochemistry: The black angel lead‐zinc mine, Greenland

The Black Angel lead‐zinc mine operated from 1973 to 1990 using seawater in the froth flotation mill process and submarine tailings disposal to the Affarlikassa (“A”) fjord. Within 1 year from startup, elevated lead and zinc levels were found in Qaumarujuk (“Q”) fjord outside the receiving “A” fjord. Elevations in cadmium abo were found at a later date. Extended geochemical and oceanographic studies established that the ore and the tailings contained significant oxidized lead and zinc minerals soluble in the ambient pH seawater and confirmed that seasonal under‐ice destratification of the water column allowed dispersal over the sill between the “A” and “Q” fjords. A shoreline waste rock dump also contributed to the contamination. Detailed mineralogie, leaching, and oceanographic studies, which are now conventional at proposed new mines, would have produced more detailed information on which to base the decision whether submarine tailings disposal (STD) was appropriate at this particular site.

Review of 23 years of STD: Island copper mine, Canada

The submarine tailings disposal (STD) system at Island Copper Mine has been subjected to a comprehensive environmental monitoring program initiated in 1970, some 20 months before the mill started processing ore. The program has been extended and modified as new factors became relevant or it became clear that particular factors were not of concern at this site. The major environmental issues have concerned (1) tailings resuspension and upwelling, (2) smothering of benthos, and (3) trace metal contamination from acid rock drainage (ARD). A closure plan has been prepared for implementation in 1995. Tailings were resuspended and upwelled to surface close to the fiord sill due to unpredicted periodic high‐density tidal jets scouring the deposits at that point. The localized elevated turbidity has not affected biological productivity. Benthos have been smothered under rapid tailings deposition such that areas under thick tailings ( > about 20–30 cm) showed reduced biodiversity. At deposition rates of < l cm p.a...

Benthos on tailings beds from an abandoned coastal mine

Abstract The marine benthos which had recolonized the site of a mine tailing discharge 12 years after mining activity had ceased was compared to an adjacent area in which no tailings were found. Test (tailings) and Reference (no tailings) sampling stations consistently separated in a series of 6 cluster analyses. They invariably provided the last linkages, thus demonstrating that biological differences between tailing and non-tailing areas remain after 12 years. Tailing station faunas were less diverse than those at non-tailing stations, and each had characteristic faunas. Shallow (25 m) and deep (100 m) stations clustered together for both Test and Reference transects, but were significantly different (P

Aspects of Histology in Macoma Carlottensis (Bivalvia: Tellinidae) and In Situ Histopathology Related to Mine-Tailings Discharge

Macoma carlottensis Whiteaves, 1880 is abundant (up to approximately 350 nr2) in subtidal infaunal communities on the continental shelf of western United States (Lie & Kelly, 1970; Word, 1979) and in British Columbia fjords (Ellis, 1969). Of thirteen different species of Macoma identified from the coastal waters of southern British Columbia, M. carlottensis is the most tolerant to variations in water depth, sediment particle size, current exposure, and salinity (Dunnill & Ellis, 1969). Observations of the species maintained in sediment trays in our laboratory suggest thatM. carlottensis is an infaunal, primarily sub-surface deposit feeder which generally lies at a depth of 1-4 cm with its left valve downwards. Filter feeding was observed in some instances as indicated by extension of the siphons from 0-5-3 cm above the substrate.

Submersible surveys of benthos near a turbidity cloud

Abstract Seabed impacted by settling solids from a turbidity plume can be surveyed by submersible using a ‘bounce’ technique to determine depth of the turbidity front, and hence depth above which benthos observations are practical. The protocol adopted was that after frontal depth was determined by a preliminary dive, the site for the benthic survey was selected. On arrival on the seabed a reconnaisance was made for the observers to agree on the identification of visible benthos. Then 100 × 1 m 2 transects were surveyed using a 1 m 2 quadrat attached to the submersible in view of the port-side observer. At the site investigated, two shallow water stations (depths 13–15 m, and 16–18 m) showing light deposits of mine tailings were seen to support associations of large epifauna and infauna. The first station had an almost single-species stand of the burrowing anenome Pachycerianthus fimbriatus at approximately 100 · 100 m −2 , and the second a diverse species association with several starfish and other species at 1–2 · 100 m −2 . Burrow holes (up to 3–5 cm diameter) of various sizes indicated that large infaunal species were present. At a deeper station (36–27 m) with heavy tailings and almost no burrow holes, a single Dungeness crab, Cancer magister , and an unidentified shrimp were seen in the 100 m 2 transect. Each dive site was inshore (shallower) from a routinely monitored benthos station shown repeatedly to support a population of small infauna in the tailings. Burrow holes have the potential for determining the identity and abundance of large infaunal species present if an identification system can be developed. The technique of epifaunal and burrow hole surveys (by submersible and scuba diver), combined with infaunal and sediment core surveys and contemporary theory on infaunal succession, provides the potential for a procedure to map the distribution in shallow water of tailings impact and benthic recovery (succession).

Rocky shore intertidal zonation as a means of monitoring and assessing shoreline biodiversity recovery

There are times when an old concept of science can be used for a new application. As an example, over many years to 1972, Stephenson and Stephenson (1949, 1972) developed the concept that there was a global pattern to biological intertidal zonation on rocky shores. This pattern of zonation also occurs on rocky–stony beaches, wherever the rocks are large enough for biological colonization (Fig. 1). It is this feature which can nowadays be useful for assessing biodiversity recovery. Wherever a pre-existing marine shoreline has been covered with rock and stony fill, the appearance of the intertidal zones should follow a succession to the eventual ‘‘climax’’ or equilibrium community, i.e. the global pattern of zonation. The following will show that the concept can be used for environmental monitoring purposes, an essential practical component of the Precautionary Principle (Tickner and Raffensperger, 1999). There are considerable logistic benefits in using the approach.