It was a year ago I woke one morning to the strong choking smell of heavy fuel oil in the air and the haze of a major storm and huge surf. On the way to work I stopped at the local Surf Lifesaving Club where I was a patrol captain and part of the leadership team. To my dismay the beach was awash with 300 tonnes of heavy fuel oil that had come ashore from the MV RENA container ship. RENA was high on a reef some 20 km offshore, having been stuck hard for a number of days during calm weather. I present here some personal thoughts providing a broad overview of the experience and insights into the complexity of events.
For several days prior to the spill comments from the public were rife with such statements as ‘just pull it off with tugs’, ‘get a barge and just suck the oil off’, ‘get some cranes and just lift all the containers off”. The public were also trying to access the beach and fill plastic bags with toxic relatively unweathered heavy fuel oil. I was surprised at how little many people understood about the maritime industry and marine environment. During the days prior the spill response had been gathering momentum, with an HQ set up and the command structure finally sorted, wildlife recovery setup underway, oil spill response plans implemented, and an inundation of people wanting to help.
We teamed up with the University of Waikato and Regional Council to plan and carry out a Rapid Response Survey of reefs likely to be impacted by oil leaking from the ships breached hull. The reef areas surveyed provided a baseline comparison for events that were to unfold in days to come. A baseline Polyaromatic hydrocarbon (PAH) level in flora and fauna was determined to work off along with knowledge of the distribution and abundance of key reef flora and fauna.
As an ex-regular Navy watchkeeping officer and reserve unit member in Tauranga I had the opportunity to fly out to the RENA on an airforce helicopter. I was winched onto the quarterdeck of a Navy ship patrolling the exclusion zone and providing command support for Maritime New Zealand operations. As we flew over the spill we could see the slick stretching off the beach and out to sea for several kilometres. Containers had washed ashore and spread debris along the beach in places. The salvage crew were winched onto the bow of the RENA.
A major problem with the RENA was that the heating coils keeping the oil warm for pumping around the ship were no longer working. ‘Cold’ heavy fuel oil cannot simply be pumped off a ship. A ‘cork screw’ type device had to be used to literally pull the oil up and out onto the barge through hoses. Also, some tanks were more inaccessible due to the position of the ship on the reef and the breached hull. Oil had to be pumped into adjacent tanks and then out.
Being a container ship many containers were lost overboard and either sunk, drifted semi-submerged or washed up along the beach. The salvage company organised to detect them using survey equipment and to tag them with buoys and GPS locators until they could be picked up.
Modelling had accurately identified the direction of the slick and in days to come predicted where it would progress to along the coast. Some sensitive estuaries and harbour entrances existed. There was concern about oil washing into ecologically sensitive areas. Booms were placed across some areas where it was calm enough and the entrance small enough to do so. A lot of noise was made about the use of booms offshore and along the coast. But their effectiveness is limited in an open coast surf zone, increased wave action and heavy seas.
Meanwhile beach cleanup was being coordinated and the army called in to head up operations. The regional council had a register of volunteers that were also organised. The three Surf Lifesaving Clubs acted as focal points for operations. Cleaning up a surf beach is an enormous task and many tonnes of sand contaminated with oil was removed to a designated landfill containment area for burial. The oil had also formed a layer about 10 to 20 cm below the sand which washed up with changing tides. Finer tar balls were sieved with shade cloth by hundreds of individuals moving along the beach in lines over a number of weeks.
With working across the Navy, Surf Lifesaving, and being involved in the ‘environmental’ response through the tertiary sector and Regional Council I gained valuable insight into some of the problems, issues and lessons learnt about responding to a major spill. A few of these are described here.
- The public are keen to get stuck in and help to the point of potentially harming themselves and the environment in the process. It is key to communicate and organise them right from the start to avoid making a bad situation worse.
- Oil accumulates along the coast over several tidal cycles so it was pointless mounting a cleanup response straight away, much to the dismay of the public. The three main habitat types of open surf beach, rocky coast, and estuaries presented different issues in terms of impacts and cleanup and response.
- After removing tonnes of sand the surf beach literally had to be sieved with shade cloth, the rocky shore scrubbed with a type of absorbent bark, and for estuaries fingers crossed oil did not travel to far up and inland.
- Polyaromatic hydrocarbon’s (PAH’s) are actually metabolised fairly quickly by invertebrates such as surf clams and paddle crabs. Short-term smothering of the sand and rocks in areas was also handled quite well by infauna along the rocky shore and surf beaches.
However, because many studies base environmental impacts of toxicity on LD or LC 50’s there is little known about the long term impacts of sublethal effects on fauna. In particular, for the RENA oil came ashore potentially during the season in which paddle crabs may molt and mate and then subsequently come into berry. Little knowledge exists about impacts on fecundity, egg maturation and larval release during spawning. Downstream impacts on recruitment into the adult population of a commercially important species are not known. Many other thoughts could be highlighted here including the use of dispersants but I hope this provides at least an insight into the operational complexities of responding to a major spill event.