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Posts Tagged ‘Competition’

Sexual selection – a driving force in marine systems?

Prey are well adapted to evade predators, and predators are correspondingly well adapted to catch prey. For most of us it is pretty reasonable to accept that such adaptation happens by natural selection, leading to long-term evolution of animals, making them better to either catch prey or evade predators, whatever end of the food chain you happen to be on. Thus natural selection affects traits such as foraging efficiency or anti-predator behaviours that lead to longer lives, quicker growth rates and, both directly and indirectly, higher reproduction rates. Most of my earlier blogs have more or less built on the assumption of natural selection affecting adaptations of animals.

Bright warning colour on nudibranch. Probably a result of natural selection favouring nudis clearly advertising their poisonous properties.

Bright warning colours on nudibranch. Probably a result of natural selection favouring nudis clearly advertising their poisonous properties.

There is  another kind of selection, sexual selection, that is a little bit harder to understand. Sexual selection is the process where traits that directly affect the likelihood of securing a mate is changed over time, leading to the evolution of traits that sometimes seem to act contrary to natural selection in that sexually selected traits rather decrease life expectancy and growth rates. There are many examples of traits governed by sexual selection on land. Bird song, brightly colored males in many birds and lizards, antlers on deer and males adapted for fighting other males for access to females are examples that we all can relate to. It is thought that sexual selection in terrestrial systems are well as important as natural selection in shaping many aspects of populations and also a major force in driving speciation.

Male macaque with teeth adapted to fight other males over harem rights

Male macaque with teeth adapted to fight other males over harem rights

Are there examples of sexual selection in marine animals? Well, such examples are without doubt not as obvious as on land. The most obvious is dimorphism between sexes, that is that the two sexes differ in size.  Many fishes, such as many species of wrasses and groupers, have males that are much larger than females. Males of such species secure their mating by either fighting with other males for mating rights or showing of to females in order to make the female choose the performer.  This is certainly a sexually selected character. Some crabs seem to have very large males as compared to females, and that could be related to mating coinciding with female molting. Males can detect this molting some days before it actually happens, and try to protect “their” female from other males. Thus large males will be able to fend of smaller males, thus monopolizing pre-molting females.

Large male crab guarding female crab against other males

Large male crab guarding female crab against other males

When females are lager than males, it is very seldom a sexually selected character. In most marine monogamous species with a size difference between the sexes, the female will be the larger. This is not due to the female competing for mates, as the pair is monogamous, but rather that size affects egg production positively much more than size affects sperm production. Thus, in many cases, it makes sense for a monogamous pair to consist of a large female and a small male.

Large female false clown anemone fish with small male

Large female false clown anemone fish with small male

Another possible example of a sexually selected trait could be the extraordinarily long “nose” that some xeno crabs have. I have no idea if this is correct, or even if “nose” length of xeno crabs are related to sex, but is could be.

Xeno crab with an extremely long "nose"

Xeno crab with an extremely long “nose”

Otherwise, I find it surprisingly rare with clear sexually selected traits in marine animals. It could be related to the mating methods many marine animals use, where sex cells are released into the water and is more or less anonymously left by themselves to find a suitable cell to fuse with. This method of mating somewhat precludes mate choice or mate competition, thus making the force of sexual selection very weak compared to that of natural selection.  I will get back to mating methods on reefs and reef-near areas in a later blog.

Why good things can be bad.

In every documentary I have seen and book I have read about Lembeh, it is stated that the waters of Lembeh are exceptionally productive partly due to the currents that bring nutritious water through Lembeh strait regularly, partly due the black lava sand more or less defining Lembeh that leaks nutrients into the water. It is easy to envision that such an environment with loads of biological production would be very nice to live in for the creatures inhabiting the strait.

Wire coral gobies, feeding on plantkon that is swept through the strait by currents

Wire coral gobies, feeding on plantkon that is swept through the strait by currents

Surprisingly enough, evolution seems to have been working overtime  in Lembeh, partly shaping the foraging skills of the animals here, but even more obviously perfecting their skills of evading predators. Why is the pressure on prey animals tougher here in the seemingly benign waters of the strait than in other less productive environments?

Lizard fish with the elongated fin rays of a former sand diver in Lembeh

Lizard fish with the elongated fin rays of a former sand diver

Mathematical models of predator and prey populations give us the answer.  For every population there will be a maximum number of individuals that the environment can provide for. This number is called the carrying capacity of a population. If one increases the carrying capacity for a prey population, the prey population will increase the number of offspring that is produced. However, if there are predators around, predators will take advantage of the increase in the reproduction of the prey population, and the predators will increase their population size, leaving the prey at a low but very productive density. Thus every prey individual alive will be faced with a much higher risk of being killed by a predator than in a less productive environment, setting the scene for evolution to try out more and more bizarre and elaborate ways for the prey to survive the onslaught of the predators. Obviously there will be competition between prey on being safer than anyone else which will feed evolution with a drive to use whatever genetic variance giving anyone an advantage over conspecifics or individuals of other species.

Soft coral crab with an almost unbelievable camouflage on its soft coral host in Lembeh

Soft coral crab with an almost unbelievable camouflage on its soft coral host

Why stay here then? Is there really anything good at all living in productive environments then given that you as prey face a never-ending threat from predators? Well, it turns out that the alternative is just as bad. In prey populations that are controlled by food availability rather than predators, prey will reach densities where the food resources are heavily used and most everyone is on the verge of starving to death. The sad truth about being an animal in nature is that, with very few exceptions, you either live a life where every day is a constant struggle to make ends meet, feeding on the very scarce resources not already being utilized by someone else, or you live in constant fear of being torn in pieces by something bigger and fiercer than you are! Sucks, doesn´t it!

Shrimp seeking refuge in anemone

Shrimp seeking refuge in anemone

Luckily for me, as I really enjoy exquisite examples of prey adaptations to evade predators, many prey animals in Lembeh will be on the “lots of food around, but holy smoke it is scary here”  end of the scale. Every dive here will give even a first time diver in the area many examples of what living in such an environment does to prey animals. Also, as a nice side effect, the strait is littered with predators, which we will get back to in a later blog.

The Inaugural Lembeh Shootout has finished!

Our first Lembeh Shootout in association with Underwater.kr has just finished, and it was a blast.

We made our rules very strict, specifically in relation to trying to limit our environmental impact, as one contestant put it… ‘It was refreshing to shoot with the discipline we sometimes forget.’

We laid out the categories in the following way:

  • Compact Camera
  • Mirrorless
  • dSLR
  • Super-Macro
  • Unrestricted
  • Portfolio

Then we had additional prizes for the following:

  • Environmentally Friendly Diver
  • Best Of Show

We did not want to promote the misuse of pointing sticks, or having animals in an unnatural environment, so the guides would not move critters to unusual, more favourable positions – and the judges and the guides were also checking to see if the critter was in the same condition when a diver finished shooting as when he started.  We’re pretty sure this is unique and it did make it very cool. For the judging, we based our criteria on the usual areas of image quality, composition, technique and subject, and we also considered the amount of tweaking the image had been subjected to.  This may explain why the order of images may seem odd if you have not seen the raw files.

So, here we go with the results:

Compact

Winner:  Balqesh Abdullah

Winner Compact Category, Lembeh Shootout

(c) Balqesh Abdullah

Honourable Mention:

Honourable Mention Compact Category

(c) Hng Che Leong

Mirrorless

Winner: Christine Foo

Winner Mirrorless Category

(c) Christine Foo

Honourable Mention

Honourable Mention Mirrorless Category

(c) Anne Adijuwono

Honourable Mention

Honourable Mention Mirrorless

(c) Nicole Ng

Honourable Mention

Honourable Mention Mirrorless

(c) CH Low

dSLR

Winner:

Winner dSLR Category

(c) Kay Burn Lim

Runner Up:

Runner Up, dSLR Category

(c) Carmelo Bethencourt

3rd Place:

3rd Place, dSLR

(c) Carmelo Bethencourt

Honourable Mention:

Honourable Mention

(c) Jeong Kwon Park

Honourable Mention:

(c) Alvin Ho

(c) Alvin Ho

Super Macro

Winner:

winner supermacro

(c) Kay Burn Lim

2nd Place

runner up, supermacro

(c) Patrick Rebai

3rd Place

3rd Place, Super Macro

(c) CK Chong

Honourable Mention

Honourable Mention, SuperMacro

(c) Carmelo Bethencourt

Unrestricted

Winner:

Winner, Unrestricted

(c) Kay Burn Lim

2nd Place:

Runner Up, Unrestricted

(c) Kay Burn Lim

3rd Place:

3rd Place, Unrestricted

(c) Christian Jansen

Honourable Mention:

07_D_003_sm

(c) Won Ha Kyoung

Portfolio

Winner:

1st place portfolio

(c) Jeong Kwon Park

2nd Place

(C) CK Chong

(c) CK Chong

3rd Place

(c) Patrick Rebai

(c) Patrick Rebai

Best of Show

Winner:

Best Of Show

(c) Jeong Kwon Park

Environmental Diver

Winners:     Patrick Rebai & Christian Jansen  (Joint Winners).

A special thanks to all of the sponsors, the new friends we made and the old friends we saw again.

Underwater.kr Shoot-Out started

The competition started

Since today the Underwater.kr Lembeh Shoot-Out started. Nad-Lembeh is hosting this international Underwater Photo Competition, where Photographers from Korea, Malaysia, Singapore, USA, Indonesia and Europe compete in different categories such as “Interchangeable Lens Cameras”, “Compact Cameras”, “Portfolio”, “Super-Macro” and “Unrestricted”.

To give a good example for the whole underwater photography scene, there will also so be a Special Prize for good diving behaviour – awarded to the diver with the most respect to the marine life and the best diving/buoyancy skills. It seems to be working: The judges saw very good behaviour on the first day of the competition. Also good … No flooded housings so far. The only thing that actually went wrong today: Simon had to do his first dive as a judge without fins, which had been left in the resort 😉

A big thanks goes to all the sponsors, that donated the huge prize fund and special thanks also to the sponsors that are here on site: Nauticam, Eneloop Malaysia and Cam Square.

Photo Tips: Introduction

With everyone shooting digital and huge memory cards it is quite easy these days to take 100+ photographs in a dive, especially in Lembeh.

The key to getting a good photo that you are still happy with by the time you go home is to take your time and keep using the image review button.  Here at NAD we have started to make a recommendation of take 5 photos, nice and slow, then pass the subject on to someone else if they are waiting.  Whilst they take their 5 shots you can take a look at what you shot and find the problems and try to correct this for when the subject gets passed back to you.  This was brought about by a bunch of serious photographers agreeing (our stand in blogger, Bent, was one of them) to be more civil to each other in this way, and they actually found that they ended up with better photos than had they just blasted away for several minutes.

In the old days of film we were always taught to bracket, as it may be weeks before you get to see your developed pictures – so take several and pick the good one later on.  So you would bracket your exposure, and sometimes your strobe position.  Writing down the frame number and technique on a slate, then transferring it to a book back on the boat between dives.  Fast-forward to getting your slides back a week later you would check each slide, hoping that your numbering came through and find the best one and check what you did in the book, and try to remember it.  Very tedious isn’t it?

With these digital cameras to do all that, instantly, all you have to do is press the ‘play’ button to look at it straight after you shot it.  So my question is, why are some people too lazy to do that?!

There really isn’t much excuse for saying at dinner, “my shots were all bad, I need to go back to that divesite again” – unless you had malfunctioning equipment or a malfunctioning buddy kicking up silt in all your photos.  Going back to a divesite because it was orgasmically good, is of course a completely normal excuse!

I will admit of course I have done the above myself.  Getting caught in the moment and not checking the image review and then coming back with a memory card of junk photos where a strobe was out of battery, iso was set to 6400, etc etc

There is a big difference between shots not being good enough, and shots being just plain bad; if they are plain bad, you need help, probably a course.  Either  a quick freebie refresher from me to make sure your camera is working properly (free means a quick 20 minute run through 😉 Not me looking at every out of focus picture you took), or maybe a paid course with me where I come diving with you and watch what you are doing.

If  you are reading this and nodding your head repeatedly at all the mistakes  laid out above, you might want to do a workshop with someone like Mike Veitch (he has a workshop here next year). People like Mike (I used to work with Mike on these workshop weeks in the past as well) do these intensive weeks of tuition where that’s all it is about, learning – no other distractions.  Now I have a resort and a baby so my time is more limited. So if you really want to learn a lot I totally recommend coming to the Underwater Tribe workshop in April.  Mike and Luca will just be teaching, they wont dive with their cameras, their focus will be on you.

I will be blogging about some techniques and tips over the next few weeks leading up to our Photo Competition that might be of help to some of you. They might also be useful for the experienced photographers out there as well, as a good photographer is always learning – I find myself learning to shoot all over again after a few years of being ‘dry.’  My first post will be about Bracketing, and will be coming soon…

 

Photo Critiquing at NAD

The Diveguides doing group critiquing at the end of a days shooting.

Win free spot for Underwater.kr Shoot-Out @ NAD Lembeh

As mentioned before NAD Lembeh will host a UW Photo Shoot-Out organized by Underwater.kr this december (8-15). The whole resort will be blocked for the Shoot-Out – prices are over 35.000 US$ Value and include Cash Prices! Now Underwater.kr announced a Online Photo Competition to win a free spot for the Shoot-Out (Value: 965 US$). Please check the Competition Page for Details. Good luck to all participants!

Underwater.kr Lembeh Photo Shootout 2012

Shootout at NAD Lembeh Resort

NAD Lembeh proudly announces, that underwater.kr will be hosting a UW Photography Shoot Out at NAD Lembeh Resort this December.

Date: 8~15th Dec 2012
Location: NAD Lembeh Resort, Lembeh Strait, North sulawesi, Indonesia
Prizes: Over US$35,000 including Cash prizes.
Please note, the list of great prizes will keep growing so please keep visiting Photo Shootout Page to see what’s new!

* 08th : Registration & Orientation, Welcome Function
* 09 ~ 13th : Dive Photo Contest, Photo Seminar
* 14th : Awards Ceremony
* 15th : departure from the resort

Official Underwater.kr Photo Shootout Page: http://www.facebook.com/UnderwaterkrPhotoShootout
More detail will be here: http://underwater.kr/shootout/2012/
Photo Contest Rules: http://underwater.kr/shootout/contest_rules

Judges: Simon Buxton plus other judges TBA

Sponsors:
– NAD Lembeh Resort
– Nauticam International Ltd.
– Maluku Divers
– Cam Square
– GoPro for UnderWater
– FUN-IN Underwater Photo Equipment Co., Ltd.
– Halcyon Korea
– INON
– more TBA.

Media Partner: ScubaNet

Package Price: US$965.00/person (ROH)
Package Inclusions:
* Accommodation (Twin share basis)
* All meals, morning and afternoon snacks
* Guided boat dives x 17 (air)
* unlimited Self-guided House Reef diving
* All tax
* EXCLUDE: Airport Transport: USD$40/car/max 4pax/one way

For book your seat, please contact uwkps@underwater.kr