Tuesday, February 1, 2011

Stingrays


Norfolk Island has a mostly rocky coastline.


The sandy beaches we have are beautiful and within the reef at the southern end of the island (at Emily Bay and Slaughter Bay, in this picture) the swimming is safe and snorkeling reveals amazingly diverse and interesting marine life. It is especially remarkable given the comparatively small area that so many species of coral, fish and other marine life are found there.  Norfolk's coral reef is the second most southerly reef in the world.


The volcanic origins of the island also provide interesting rock pools formed from lava beds and eroded lava tunnels. A lifetime could be spent examining these small worlds, which provide safe havens for many species and fish nurseries in some where masses of coloured juveniles start their lives.



One of the island's favourite rock pools for snorkeling is called Crystal Pool. It is at Point Ross on the south western end of Norfolk with an access track that assists in keeping the area from being overcrowded, by being a little challenging. It is not recommended to swim there in big seas, as waves have been known to wash into the pool and occasionally take the unsuspecting snorkeler for an unexpected dip in the ocean. Local knowledge about suitable conditions is always wisely sought, anywhere we travel, and that applies equally here .

Similarly, big seas can wash unsuspecting creatures into the pools from time to time, and it is probably for that reason that a large number of stingrays appeared there recently.
The photos here show some of a group of stingrays that found their way into the Crystal Pool in December 2010.
  

There was a group of about 20, which were possibly just some of an even larger aggregation, some of which were washed into the pool and stranded there for a few days. Very rough seas and high tides had been experienced shortly before the time these were seen. 
Mark Scott (seen here patting one of the rays) provided these photos. Mark's enquiries about the presence of such a large number of these rays led to Jack Marges who ran Norfolk's scuba diving company Bounty Divers, for many years.  Jack has seen large groups of male stingrays regularly but more often encountered them in the open ocean, or tucked away in more open bays and usually a little later in the summer, around February. Large groups have been seen by others at Anson Bay over many years as well.  Jack's previous experience with rays identified them as the Blotched Fantail ray (Taeniurops meyeni)  which was confirmed by Malcolm Francis, a New Zealand-based researcher .(In older publications on Norfolk fishes, this species was called by the earlier names Taeniura meyeni or Taeniura melanospila.)
Mark noted that all the rays were male (identified by the 'claspers' either side of the tail), and Malcolm said that so far it is not known why they gather together this way, however local observations confirm that it is a regular summer event.

There was a further  report of about 26 (possibly) rays seen near shore at Anson Bay in December also.

The group in Crystal Pool gradually reduced in number until there were 3 during the first week of January, and shortly after that they were all gone.


The current operator of Bounty Divers tells me that there have been consistently high numbers of rays being sighted at dive spots around the Norfolk group of islands, particularly at a dive spot known as Swiss Cheese, south of Norfolk.

The water temperature at Norfolk continues to warm
up well past the heat of summer, and swimming in the crystalline waters, surrounded by beautifully coloured fish and interesting corals, anemones and fascinating hard-to-define marine life forms can be enjoyed all year round with only a light wetsuit (if any) required even in the winter.
More underwater images will appear here before too long.


I'm off to the beach now!
Thanks to the Norfolk Island Visitors Information Centre for the aerial image of Emily and Slaughter Bays, and of the snorkelers in a small part of Crystal Pool. Special thanks to Mark Scott for providing this observation, images and research.

2 comments:

  1. Great article and pics ... thank you! My family and I snorkelled in Crystal Pool in late January 2011 and found 3 of this type of stingray in the first bowl shaped pool. In the longer pool, however, there were two much larger stingrays. Could they be Smooth or Black stingrays ... they were of a very considerable size. When we returned a few days later, the big ones were gone and there were 9 of the smaller ones in the first pool.
    Regards, Stu

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  2. Thanks for that Stu. I'll ask around and see what I can find out about the larger rays you saw. Interesting that you saw them late in the month.
    cheers
    Margaret

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