Crab Hunting In New Zealand

[Doctor Mud]

Hi everyone,

I hope you have all had a great holiday season. I travelled back to New Zealand to spend time with my parents in their new post Christchurch quake house. They now live about 1 hour drive away from the north Canterbury stretch of beach famous for fossil crabs - in particular the giant Tumidocarcinus giganteus.

During my last visit to New Zealand I visited this beach and walked away with a nice little "starter" crab from this site. Erosion had taken its toll. The underside prepped nicely and one claw was intact, but a pincer was missing from the other and most of the legs were gone. I had so much fun prepping this one (I still have a bit to finish off), but I wanted a more complete specimen. One of my goals for this trip (apart from avoiding eating too much over Christmas!) was to collect a nice big complete crab.

Well - I failed with the first goal. Home cooked meals and travelling around NZ and eating out were too tempting. Lucky this can be balanced out with long walks in the outdoors - often in areas where a nice fossil can be encountered! I planned at least two trips to the Canterbury coast to increase my chances of getting a nice crab. Could I achieve my second goal of this trip?

My first visit was with my girlfriend. She likes to dabble in a bit of fossicking but usually ends up sitting in a camping chair on the beach enjoying a good book while I roam around with head down looking for fossils. I did a systematic grid search of the boulders below one of the closest cliffs to the access track. Unfortunately after hours of looking - no crabs! I did find a concretion with a tooth sticking out which was a bonus. I have no idea how big or complete the tooth will be yet. Looks like at least the root is missing (lower image in picture below). It wasn’t the tooth that caught my eye initially but the strange hole in the rock (upper image in picture below).

So, I was a little disappointed that I didn’t manage to find that big intact crab I was after, but I promised myself another attempt before I return to Australia. My opportunity came yesterday to revisit the site. I planned my hunting trip the night before on Google Earth. I reasoned that the closer cliff is probably well picked over so I needed to get to a beach with the right sediments that has not been visited very often. My father came along with me for the trip. He is not able to walk far these days but was happy to sit in the car reading and also to keep in touch via cell phone for safety on the beach. Low tide was at 2 PM, so I got myself down on the beach by 11 AM and planned to get to my remote beach location by before low tide and work my way back.

It was hard work scrambling around the coast line through the jagged boulders but I finally made it my target location. I only met two other people on the beach – a local couple who were diving for Paua (Abalone). As soon as I got to my location I had a good feeling….there was no evidence of boulder splitting and there were many boulders of the right rock full of beautiful corals and shells….a good sign! I dropped my pack and started to walk slowly along, eyes down looking for signs of crabs. Then, I saw it….a large stone with the tell-tale rings where the eroded crab legs were poking out of the rock. I checked – 4 rings on each side. This was my first complete crab !!! and a decent size too. (See images below).

I planned to walk to the next point and then return to my pack for lunch. 5 minutes later: crab number two ! The leg rings are there, but not quite as clear. I was pretty sure this was a crab though. (See images below).

Well I sat down and ate my lunch and enjoyed the excitement of my first whole crabs and the beauty of the rugged coastline. (Picture below). You can see what looks like an island in the distance. This is actually a peninsula attached to the Canterbury plains. This peninsula is the remains of multiple volcanoes that erupted in the Miocene - around the same time as the sediments containing the crabs were deposited.

I had set myself a “bag limit” of two crabs for the day, this was my goal and I would return straight back to the car without really looking after that. This is partially since they are so heavy (and the hill at the end is so steep!) but also I don’t want to take too many crabs at once, and I will be a while prepping these ones!

I quickly scrambled around the rocks and met up with the Paua divers on the way back. The Paua (Abalone) were all below the legal size unfortunately. The couple knew of the big crabs that were to be found here and they said they stumbled upon them usually while not actually looking for them. I joked that this seemed to be one of the “rules” of fossil hunting. You find fossils while you aren’t really looking anymore or they start to turn up when you have to leave.

After this chat I made my way further around the coast focussing mostly on getting safely from boulder to boulder with the extra 10 kg of rock in my pack. Then, I just about stepped on what I thought at first was a non-fossilised crab carapace. But no – it was the top of a fossil crab nicely exposed by nature. How ironic given my recent conversation about finding fossils when not really looking.

I dropped my pack and bent down to pick up the concretion. It turned out that the concretion was in situ and the base was still embedded in the siltstone. I felt really lucky that of all the people that would have walked over this beach during the years I was in the right place at the right time to find this.

I levered the concretion off the siltsone with my pick, wrapped it up in Newspaper, stuck in carefully in my pack and headed back to the car. I was tired and sore at the end of the day but this trip well and truly exceeded my expectations. I’m looking forward to prepping these guys out when I get the chance back in Australia.

Well that’s enough from me. I hope everyone else had exciting holiday fossil adventures !

Edited January 5, 2014 by Doctor Mud

[Doctor Mud]

Hi guys - I had problems pasting images into the text (I'm on a different computer). Sorry you have to scroll down to the bottom and hover over the images, but they are labelled so you can follow along (first concretion, second concretion, etc.) I'll try and fix it when I am on my own computer.

[Ludwigia]

Thanks for the detailed report. Sounds like you've had a very nice little adventure and a successful hunt. The concretions look quite promising, so I'm already looking forward to your preparation updates.

[jon]

Great article and good luck prep'ing them, they look good.

[CH4ShotCaller]

Vera nice! Good report, finds and pics!

[Uncle Siphuncle]

sounds like a banner outing! persistence often pays out nicely.

[jpc]

Nice concretions. And great trip report. Looks like you got some beauty's in there.

[fossisle]

Wow Wow Wow Love those concretions!!!

That last one is so awesome easy to see where to prep

[Dave pom Allen]

always a great day out when you go to Mt Cass (glenafric) i love the north canerbary coast

[DLB]

Those are some nice cons great job finding them. Wish I could find some like that. One day I may get the chance to fly out there and find some hopefully.

[JamieLynn]

fascinating. I would not have known what to look for -so thank you for the "instructional"! Now I REALLY want to visit NZ!

[6ix]

Good stuff, should have given me a yell, I'm only 20 minutes from there. Hmm, looking at your concretions I might have to go have another look at some of mine!

Keep us posted on your prep!

[Ash]

Can't wait to see these prepped!

[lissa318]

How exciting! Congrats and can't wait to see them prepped!

[MakoMeCrazy]

Wow. awesome finds!

[Doctor Mud]

Thanks everyone!

I have been looking forward to visiting this site all year and I am very happy to have found some good concretions.

Sorry for the slow reply. I'm back in Australia now and fortunately all my specimens made in through customs. I don't get to do collecting very often so I made the most of it while I was in New Zealand. I had to go and get myself a snap lock tub and check in an extra piece of luggage since I brought back 30 kg of rock!

Coming into Australia all they were worried about was any potential soil attached to the rocks. I had scrubbed all my samples clean with hot soapy water and removed any limpets and barnacles from the concretions.

[Edit: given my comments below about misuse of resources I thought I should clarify that most of this 30 kg is micro matrix for research and I impose a "bag limit" each time I collect concretions]

Edited October 15, 2014 by Doctor Mud

[Doctor Mud]

fascinating. I would not have known what to look for -so thank you for the "instructional"! Now I REALLY want to visit NZ!

You are welcome JamieLynn.

The trick at this site is to make sure that you have multiple rings. Sometimes there are tusk shells (Dentalium) in the sediments and they can look like a crab leg. If you have several rings on each side, opposite each other you can be sure you aren't seeing Dentalium.

[Doctor Mud]

Good stuff, should have given me a yell, I'm only 20 minutes from there. Hmm, looking at your concretions I might have to go have another look at some of mine!

Keep us posted on your prep!

Hi 6ix,

I will certainly get in touch next time before I visit this site again. I'm not sure when I will next be over to NZ, but I will be sure to let you know!

Good luck with your concretions. I hope they contain crabs!

Post some pics if you aren't sure.

[bruce]

Does anyone know the current status of laws regarding taking Tumidocarcinus crabs out of the New Zealnad? Hettie’s Rock Shop in Christchurch has this warning on their fossil crab page.

"Sorry we are unable to sell crabs to international customers at the moment due to New Zealand legislation."

[Doctor Mud]

Hi Bruce,

Good question.

Although not specifically stated - I believe there might be a difference between taking them out of NZ and selling them for profit. Hence why Hettie's won't sell them.

See the New Zealand protected objects act: http://www.mch.govt.nz/nz-identity-heritage/protected-objects

Export or sale of specified objects is illegal.

Schedule four: Categories of protected objects: 5. Natural Science Objects.

(3) Objects in this category include—

a. a category of type specimen as defined by the current edition of the International Code of Botanical Nomenclature, the International Code of Zoological Nomenclature, or the International Code of Nomenclature of Bacteria: Bacteriological Code:

b. a specimen considered to be scientifically important for defining a taxon through having been illustrated in the original description, or new material subsequently illustrated (that is, hypotypes) and used to expand or refine this description in the scientific literature:

c. a specimen of an extant or extinct plant or rock or mineral, animal, or other organism or fossil or part thereof including any developmental stage, shell, or skeletal or supporting element, of which there is not a sufficient selection in New Zealand public collections to define the variation, range, and environmental context of the taxon or object.

Why then could selling still be illegal if they don't meet the above criteria?

I had wondered myself about this statement as I have seen it as well. Since T. giganteus specimens are common (see the large collection in the Canterbury museum) then these specifications don't seem to apply. The T. giganteus specimens are not new or type specimens. The problem could be the gradual depletion of the resource and loss of "in situ' specimens but I believe this is just as much an issue for locals.

To me though the spirit of the law is to prevent wholesale stripping of the deposits for profit so there aren't any left in situ for future science and protection of type specimens or specimens new to science. Therefore amateur collectors taking one or two out of the country might be o.k. but companies "strip mining" the beach and selling crabs would not be.

Hence - perhaps to prevent the 'dam breaking' and mass exploitation of these fossils the government wants to ban people from selling them.

This is just my theory and I have not enquired about this.

I don't see any difference between private collectors in New Zealand and overseas collectors collecting them and taking them away for prep. and keeping them in their private collections in their homes. The availability of the specimens is still dependent on the individual being (1) aware that they have a scientifically significant specimen, and (2) being prepared to donate it to science.

All my opinions are open to debate of course!

Edited October 15, 2014 by Doctor Mud

[jpc]

Bruce.... let's go to NZ and find us one each. Nice to see you back on here.

[Doctor Mud]

Bruce.... let's go to NZ and find us one each. Nice to see you back on here.

My answer was a bit long-winded sorry!

Short answer is - there isn't a problem with private collectors taking them, I think selling them from NZ is a no no.

If you guys make the trip "down under" I'd love to take you to "crab heaven"

If not once I have prepped out some good'ins ill be in a position to maybe trade concretions.

[jpc]

Thanks for the nice invite doctor mud. I was there actually back in, well, let's just say before thefossilforum. Found a few pieces of tumidocarcinus. It is a long way from here, but ya never know.