The cause of the strandings is unknown and involve a new type, the
Willyama seahorse.
These strandings involve a new type of
seahorse, the Willyama seahorse (Hippocampus sp. 1).
The cause of the die offs and strandings
remains unknown and is a major conservation concern of the Inshore Fish
Group.
'Some of the original
57 Willyama Seahorses collected by Adrian and Kathy Brown at Marion Bay
in June 2006. These are adult males and females without any apparent
signs of trauma.'
The strandings warrant extensive investigation from conservation and
biological perspectives. Are the strandings natural or a result of human
activity? How long have strandings been occurring? Where did the
seahorses originate? What is the taxonomic status of the Willyama
seahorse.
The cause of the
strandings is a mystery and the IFG is concerned.
The information below is a preliminary
part of the IFG investigation into the Willyama
seahorse standings in South
Australia. Any further information regarding the stranding of
seahorses, seadragons, or pipefish contact Karen at
ifg.bioteck@gmail.com.
The ‘Inshore Fish Group’
became active in the investigation of the mass strandings of large
numbers of seahorses stranded at Marion Bay and Foul Bay, southern Yorke
Peninsula, South Australia from March - June 2006.
Conservation is a priority of local coastal communities in southern
Yorke Peninsula.
Images from left to
right; 1) Adrian Brown and Robert Browne on the sand flats at Foul Bay;
2) Marion Bay from the Penguin ;
3) Open ocean from Penguin Point south of Marion Bay; 4) An Australian
pelican on the sand flats at the south end of Foul Bay.
The galvanizing event
resulting in our investigation was the collection of 57 Willyama
seahorses collected at Marion Bay in June 2006 by Adrian and Kathy
Brown.
The Willyama seahorse (Hippocampus
sp.).
The stranded seahorses
did not conform to either of the two seahorse species known from South
Australia, the Pot-belly seahorse (Hippocampus abdominalis), and
the Short-snout seahorse (H. breviceps).
We named them the
Willyama seahorse after the wreck of the Willyama as suggested by Adrian
Brown.
The IFG has given the common name Willyama Seahorse to this new type in
recognition of the site of the mass strandings which is characterised by
the wreck of the Willyama. The Willyama was stranded at Willyama Beach
near Marion Bay in April 1907 almost exactly 100 years previous to the
strandings of the Willyama Seahorse.
The Willyama seahorses stranded were most similar to the short-snout
seahorse but had a different number of rings under the dorsal fin and a
coronet or crown with five radial bumbs instead of the four in the
Short-snout seahorse. See
Willyama Seahorse species profile, and
Seahorse "Species Key" and "Meristics Table" for
Southern Australasia.
A global perspective
To elucidate the history
of the strandings approaches were made by the IFG to institutions and
individual across the world asking for any information they knew about
seahorse strandings. The SA Museum collection was investigated. There
were no global reports of mass strandings, and the only records besides
those in the Lower Yorke Peninsula area of mass stranding was an
anecdotal report of a mass stranding of seahorses at Ceduna, South
Australia. Historic strandings of syngnathids in southern Australasia
have included Leafy seadragons (Phyllopterix equix) and Weedy
seadragons (Phyllopterix taenolatus).
Cause
Strandings of numbers of estuarine and marine fish can be caused by
factors from industry or marine exploitation including pollution, exotic
disease or fishing or aquaculture activities. Natural strandings can be
due to natural causes such as sudden temperature or salinity change, or
rapid changes in depth, or biological causes including endemic disease
or age.
We have not found
compelling evidence that the strandings of the Willyama seahorses are a
result of inclement weather or exceptional currents. The stranding in
June and July 2006 occurred during relatively calm weather. We looked
at 57 specimens from a stranding event in June 2006 and found that there
were an equal number of males and females. In July 2006 another mass
stranding occurred which was dramatic enough to warrant an article in
the ‘York Peninsula Times’. This time Adrian Brown collected about 300
specimens. Pathology reports from this stranding conducted by a
government agency were indeterminate due to the poor condition of
samples. There
were no other fish species stranded with the seahorses.
Recent records of seahorse strandings on southern Yorke
Peninsula
16th
December 2006. Conversations with Val Lloyd of Marion Bay revealed that
there were ‘drifts’ of many thousands of seahorse in Foul Bay, Yorke
Peninsula during early spring 2006 (July - September).
19th
July 2006 TV news report, Seahorse strandings Foul Bay, many hundreds,
attributed to ‘natural phenomenon stormy weather with onshore winds'.
Government officers collected samples for processing. Adrian Brown
collects and lodges 300 specimens with South Australian Museum.
14th
July 2006 many thousands stranded at Fowlers Bay, anecdotal.
12th
June, 2006. Marion Bay, Adrian Brown ‘there was not other significant
debris washed up with them – just algal floats, a few pieces of Scaberea
or Cystophera species, perhaps two or three toadfish’. Adrian Brown
lodges 57 specimens with south Australian museum.
Early April 2005,
21/07/06 Helen Croft, Pt Moorowie. Numerous seahorses in floating
seaweed around Haystack Island, Yorke Peninsula.
Innis, Fowl Bay, April 2002, dozens of seahorses.
Personal observations of strandings
Dr. Keith Martin-Smith,
Senior Programme Manager, Project Seahorse, School of Zoology,
University of Tasmania.
” It sounds very unusual. All of the events I’ve heard about involve
people finding only one or two animals washed ashore, definitely not in
the numbers that you’ve witnessed. I’ve heard of a couple of cases where
numbers of seadragons have washed ashore after storms in the Bass Strait
Islands. I wonder if what you’ve seen is related to some stuff that I
was contacted about last year – some people were diving around Haystack
Island (Yorke Peninsula) and saw a whole bunch of big-bellied seahorses
(Hippocampus abdominalis) rafting on seagrass.”
Dr Genevieve Mount,
Marine Research Officer, South
Australia. 11th Dec, 2006.
I have some friends who
have land near Foul Bay along the coast of Yorke Peninsula and I have
been staying with them quite a lot over the last month or so. They found
hundreds of seahorses washed up out the front of their property and said
that other local's had also found hundreds, all of them dead. This
weekend we went to Butler's beach and saw probably close to a thousand
around Butlers Beach in some of the more protected, less visited coves.
All of them were along the high tide mark and seemed to have been there
for a long time. I collected maybe 60 or so.
I think the
strandings would have been over the last couple
of months rather than the winter ones, but its hard to know for sure as
my friends only just moved back to their property in about September but
it was more like early November when they went for a cruise in their
boat around Foul Bay, Point Yorke etc and went into some of the more
isolated areas that they found the majority of the seahorses and it
might have been a month or so earlier that a number of other locals also
collected bags full of them around that same area. I'll check with them
for sure next time I see them.
I saw your article in the Marine Life
Society of South Australia Inc. October newsletter online and was glad
to see that others were aware of the issue. My friends that own the land
close to Foul Bay do a lot of snorkelling outside their property and are
pretty sure they have seen these particular seahorses alive offshore in
the past. They also heard stories from fisherman of the water being so
thick with seahorses a while back that they had trouble fishing.
From David, TEXT
FROM IFG STRANDING SEARCH ON
www.seahorse.org
Refers to stranding at Ceduna Bay, South Australia.
"Look at the weather pattern for the last south oz stranding, think
about it, the day of the strandings, where was the wind from, and at
that time of year how often does that happen, almost never.
Understanding pots and the time of year, and the most unusual weather
pattern will give you the answer.
Quite from: A Fishers Tale
by Ben Simms, ISBN 0-646-41720-7
"In 1946 there was a year of small seahorses-hundreds of them-snapper
were full of them. A snapper line always had them hanging by the tail,
and the floating seaweed in the gulf had heaps of them clustered amongst
it.
Shags and cormorants built nests of them on Tippara light. I have never
seen anything like it before or since, and nobody can remember this
happening. They were washed ashore in the millions, but only for that
year - 1946"
Newspaper articles from the 'Yorke
Peninsula News - Tuesday, July 25, 2006'
'Once you got on the
beach, if you sat in one place and measured an arm's length all around,
there were literally hundreds within that area," Vanessa describes, at a
beach near Foul Bay. "We even found some live ones, and quickly put them
back in the sea. The strongest swam off very quickly, others I think
would have been too weak to survive. They weren't high on the beach but
down in the rocks, and all were generally the same size, many with their
tails still wrapped around pieces of seagrass, quite amazing." Frani,
and her children Ayla and Jack, headed down following reports people
were picking up shopping bags full and taking them home. Once on the
beach at Point Yorke, she no longer doubted that story, finding hundreds
along where the trio walked. "Fishing off Foul Bay recently, my
son-in-law caught five snapper. Imagine his surprise when he gutted them
to find around 160 seahorses in their stomachs," Ann said. "Over the
years we have found small numbers washed up, usually around April/May,
but nothing like this year. Each little heap had five or six seahorses."
Inshore Fish Group
responses to the strandings
1) Sending contacts to all known persons
that can contact us if the die offs occur again.
2) Determining the scientific status of
the Willyama Seahorse.
3) Consulting with government
pathologists to make sure specimens from future die offs are collected
in a timely manner, preserved properly, and appropriate pathologies
performed.
4) Conducting further enquiries about
syngnathid strandings.
5) Making Marion and Foul Bay a targeted
area for community monitoring and surveys for new species.
6) Making Marion and Foul Bay a targeted
area for model conservation of inshore area.
Innis, Fowl Bay,
April 2002, dozens of seahorses.
