RESEARCH OPPORTUNITY: deep-sea fish and food webs, Dec 2003

Steve O'Shea

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Two further Masters/PhD research opportunities reconstructing deep-sea food webs are presented here. Likewise, if interested in either proposal, please contact me directly on [email protected]

Many of these deep-sea fish eat squid, so it will be very interesting to see where they fit in the food chain. Alternatively, to give it an even-greater cephalopod flavour, you could examine the diet of cephalopod species; the opportunities are endless (and so little is known of the diet of deep-sea cephalopods).

1. Deep-sea food-web reconstruction - stomach content analyses of commercial fish species

Research brief: to describe all species of finfish bycatch from a single commercial fishery (E.g. Patagonian toothfish, Hoki, Orange Roughy, Oreo dories, Scampi).

Key aspects of research include:
· Examination of deep-sea fisheries finfish bycatch samples.
· Identification of finfish species, sexing, assessment of reproductive status, measurement, extraction and archival of otoliths (select taxa).
· Diet and food-web reconstruction and species ecology and behaviour by way of stomach-content analysis.
· Deep-sea commercial fishing vessel excursions.
· Processing large volumes of fisheries bycatch.
· Fixing and preserving of archival specimens (museum collections).
· Aspects of applied conservation, fisheries and ecology.

Little research has been undertaken on the biology of deep-sea fish species in New Zealand waters, and almost nothing on deep-sea food-web structure and the relationship between fishing pressure, physical and biological habitat status, and the diet of both target and incidental bycatch finfish species.

An enormous quantity of fish bycatch is taken during deep-sea trawling for species such as orange roughy, hoki, scampi and oreo dory, but most is discarded over the side. Deep-sea trawling, especially bottom trawling, not only removes apex finfish predators from the environment, but it is also responsible for substantial changes to the structure and diversity of benthic communities, often destroying expanses of deep-sea scleractinian (coral) and gorgonian (sea fan) reef, crushing myriad smaller benthic invertebrates, and modifying the physical habitat.

Identification of finfish bycatch, and determination of basic biological information (such as diet, sex, weight, size and reproductive status), from areas subject to different levels of fishing effort, with different seabed and associated invertebrate/vertebrate faunal characteristics, would provide valuable data for ongoing biological studies to determine whether any change in diet is apparent, or whether diet is in some way related to the physical and biological characteristics of the environment from which the fish were collected.

For this research project, finfish bycatch samples would be collected from commercial fishing vessels, Ministry of Fisheries scientific observers, and by actual participation in research cruises. Basic biological data would be obtained for each bycatch specimen and species, such as identification, size, weight, sex, reproductive status, and diet (otoliths [earbones] would/could be extracted and archived for subsequent study]). Finfish diet and biological data could be related to temporal, bathymetric or geographic factors, to seabed topography, benthic invertebrate diversity [similarly determined from bycatch composition or photographic imagery], habitat, and relative fishing pressure. All data could be integrated into a food web.

Therefore, the objectives of this research would be to:
1. Conduct analyses of finfish bycatch from a single commercial fishery.

2. Undertake stomach content analyses to ascertain food web structure.

3. Compare diet with temporal, bathymetric, geographic and biological variables.

4. Undertake literature reviews to compare modern with historical data (if available) on finfish diet. Determine, if historical data is available, whether any temporal shift in finfish diet is apparent. If historical data is not available, ascertain whether diet is affected by fishing effort.

Envisaged output(s):
A very interesting, applied thesis, whether Masters or PhD.

A detailed account of finfish bycatch diet from a single fishery in New Zealand waters.

A synopsis of known biological data for predator and prey species.

Reconstruction of deep-sea food webs (trophic structure).

Integration of fisheries and biological data to ascertain relationships.

Baseline data for Ministry of Fisheries and Department of Conservation.

Ideal species on which to concentrate research (for which finfish bycatch could be procured):
Scampi (Metanephrops challengeri)
Orange Roughy (Hoplostethus atlanticus)
Hoki (Macruronus novaezelandiae)
Smooth Oreo (Pseudocyttus maculates)
Black Oreo (Allocyttus niger)

.......................
2. Deep-sea food-web reconstruction - stomach content analyses of commercial fish species

Research brief: to describe the diet of a single commercial fish species throughout its recognised distribution and ontogeny (e.g. Patagonian toothfish, Hoki, Orange Roughy, Oreo dories).

Key aspects of research include:
· Examination of deep-sea fisheries commercial fish samples.
· Sexing, assessment of reproductive status, extraction and archival of otoliths (for select taxa).
· Reconstruction of diet by way of stomach-content analysis.
· Deep-sea commercial fishing vessel excursions.
· Processing large volumes of fish stomach samples.
· Aspects of applied conservation, fisheries and ecology.

As for the previous proposal, little research has been undertaken on the biology of deep-sea fish species in New Zealand waters, and almost nothing on deep-sea food webs, and the relationship between fishing pressure, physical and biological habitat status, and the diet of both target and incidental bycatch finfish species.

Deep-sea trawling, especially bottom trawling, not only removes apex and target finfish predators from the environment, but it is also responsible for substantial changes to the structure and diversity of benthic communities, often destroying expanses of deep-sea scleractinian (coral) and gorgonian (sea fan) reef, crushing myriad smaller benthic invertebrates, and modifying the physical habitat. What effect does this have on the diet of target species?

Identification of target fish species diet, and determination of basic biological information (such as sex, weight, size and reproductive status), from areas subject to different levels of fishing effort, with different seabed and invertebrate characteristics, would provide invaluable data for ongoing biological studies, and would enable some judgement to be made as to the relationship between diet and the physical and biological characteristics of the seabed, in bottom-trawl fisheries.

For this research project, commercial fish species samples would be collected from commercial fishing vessels, Ministry of Fisheries scientific observers, and by actual participation in research cruises. Basic biological data would be obtained for each specimen, such as size, weight, sex, reproductive status, and diet (otoliths [earbones] would/could be extracted and archived for subsequent study]). Diet and biological data could be related to temporal, bathymetric or geographic factors, to seabed topography, benthic invertebrate diversity [similarly determined from bycatch composition or photographic imagery], habitat, and fishing pressure.

Therefore, the objectives of this research would be to:

1. Conduct analyses of commercial fish species diet throughout the recognised range of a species distribution (or distribution of the fishery), for a single commercial fish species.

2. Compare diet with temporal, bathymetric, geographic and biological variables.

3. Undertake literature reviews to compare modern with historical data (if available) on finfish diet. Determine, if historical data is available, whether any temporal shift in finfish diet is apparent. If historical data is not available, ascertain whether diet is affected by fishing effort.

Envisaged output(s):
A very interesting, applied thesis, whether Masters or PhD.

A detailed account of a single commercial fish species diet throughout its recognised bathymetric and geographic distribution (in New Zealand waters).

A synopsis of known biological data for predator and prey species.

Reconstruction of a single commercial fish species food web.

Integration of fisheries and biological data to ascertain any relationship.

Baseline data for Ministry of Fisheries and Department of Conservation.

Ideal species on which to concentrate research (for which finfish bycatch could be procured):
Orange Roughy (Hoplostethus atlanticus)
Hoki (Macruronus novaezelandiae)
Smooth Oreo (Pseudocyttus maculates)
Black Oreo (Allocyttus niger)
 
I'm still looking for takers on either project; this would be an extremely rewarding thesis topic. It could be recast so that ONLY the cephalopod component of deep-sea fish species was described (this in itself would be extremely interesting). Perhaps I should recast a third project along these lines (it would certainly help us determine the bathymetric and geographic distributions of both predator and prey species).

Steve
 
Hey guys


this sounds like a fascinating project (& I guaruntee you'll never look at dinner the same way again!!! :lol: ) We need more work like this done and the feeling of acheivement when you id a little bitty otolith by yourself for the first time is pretty incredible!!!


I've been looking at the diet of Nototodarus sloanii (arrow squid) and there seems to be a change in prey diversity with location (all pretty speculative at this stage) but it would be very interesting to find out if other critters have the same change and you'd be maybe doing something that no-one else has !

And no I'm not being paid for this plug!!!!

J
 
Ta Jean. I have one 'heavy pencil' taker for this as a PhD project starting 2004 (whether we look at the diet of the fish, or of the cephalopod). Surely there must be more of you out there interested in spending 3-4 years dissecting fish guts, going out to sea, identifying all manner of bits and pieces from the stomachs, playing with dead squid, reconstructing food webs ... and stamping your mark on fisheries!

It IS an interesting (and unknown) aspect of deep-sea science.
 
Hi all!
Just discovered this forum (duh!) and what can i say? This is great! Extremely interested by the above projects so I'd like to know if there still up for grabs before i pester Steve with a big formal email :roll: :biggrin2:

TPOTH
 
TPOTH said:
Hi all!
Just discovered this forum (duh!) and what can i say? This is great! Extremely interested by the above projects so I'd like to know if there still up for grabs before i pester Steve with a big formal email :roll: :biggrin2:

TPOTH

Feel free to pester with a less-than-formal note (we don't worry about formalities here) TPOTH; I do have some takers for the food chain research, but the possibilities are near endless. The problem is I have no funds to offer .... I wish I had, but I'm cleaned out financially nowadays.

I'm real tight on time over the next month, but I will respond within a couple of days, if I'm about.
Cheers
O
 
Steve O'Shea said:
TPOTH said:
Hi all!
Just discovered this forum (duh!) and what can i say? This is great! Extremely interested by the above projects so I'd like to know if there still up for grabs before i pester Steve with a big formal email :roll: :biggrin2:

TPOTH

Feel free to pester with a less-than-formal note (we don't worry about formalities here) TPOTH; I do have some takers for the food chain research, but the possibilities are near endless.
They are indeed :smile: Shame companies and other states aren't willing to plug more cash into ceph research :roll:
The problem is I have no funds to offer .... I wish I had, but I'm cleaned out financially nowadays.
Then i guess it's up to me to find some cash (wonder if I have a rich uncle). However I'm a n00b in such endeavour, many applications require a complete proposal and such so I might require some help/pointers while preparing those funding applications. Anyway, I hope we'll have the time to discuss the matter in more details once your moving is over. :smile:
I'm real tight on time over the next month, but I will respond within a couple of days, if I'm about.
No rush anyhow :wink: My life expectancy is significantly longer than that of a squid so I can wait.

TPOTH
 
Burstsovenergy24 said:
:welcome: to TONMO! Nice avatar
thanks... i so wish i'd discovered it much sooner *sigh* But I'm here now
but what does TPOTH stand for?
What kinda hoping nobody would ask... Comes from years of roleplaying, what can i say? i'm a geek ... and i like squids and octopuses... hopeless :roll: :lol:
Anyway it stands for Tzimisce Protector of the Haven :oops: :oops:

TPOTH
 
Oh, I thought is was like "I'm a little TPOT, short and stout...". (No theory regarding what the 'H' was all about.) :oops:

'Tzimisce Protector of the Haven' is much more impressive. :smile:

Are you a (trained) biologist?
Neil
 
TPOTH said:
.... I'm a n00b in such endeavour, many applications require a complete proposal and such so I might require some help/pointers while preparing those funding applications.

.... you have to excuse me .... but what on Earth is a n00b? Does it require penicillin :wink:

Drop me a line TPOTH. If you've any ideas re funding sources then I'm happy to put in the groundwork on a proposal.

In the meantime ....... back to work I go....
O
 

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