Marine Ecology

Introduction

• We will spend the next several lectures looking at connections between environments.

• You’ll hear words like habitat and ecology often.

• Marine ecology puts all the stuff we’ve discussed until now into larger perspective.

Organization

• Communities are often looked at as being bioticbiotic (living) or abioticabiotic (not-living). Notice I didn’t say dead. Why is this significant?

• Organisms interact with each component in unique ways.

• Adaptation, is one of the most significant interactions an organism can undertake to ultimately succeed in it’s environment.

Adaptation to differing light regimes.

Turbinaria spp. change growth patterns according to available light.

The animals on the left live in a higher photic zone than the ones on the right.

Which one likely contains more chlorophyll??

What happens when adaptive ability is good?

Or lack of predation??

With sufficient resources (nutrients, shelter) sea urchinscan take over!

Over time they may exceed the carrying capacity of their habitat.

Carrying Capacity = max population.

Sometimes limiting resources cause intense competition between (inter), or within (intra) species groups.

These Hermit Crabs areengaged in intraspecificcompetition.

If one “bests” the other andestablishes a territorythen competitive exclusionhas taken place.

What happens in an extremecase of comp. exclusion?

Resource partitioning may play a role.

At one time, whale sharks may have contained huge teeth!To avoid competition for food, they became specialists on plankton?Has this solved their dilemma entirely??

Other animals take the opposite extreme.

Purple cone snails (Conus purpurascens) may have been effective algae eaters.

Sometimes behavior is modified in different ways to avoid competition.

Predator vs. Prey• If you eat someone else, you’re a predator.

• If you are eaten, prey.

• Most predators or prey fall into simple categories of carnivores (meat) or herbivores (plant).

• Omnivors are out there too, but given the choice they will usually choose to be either a carn. or herb.

• Detritivores aren’t considered predatory. (Imagine having a piece of decaying material suddenly defend itself!!)

What if you just take up space??

Barnacles, just sit around. As long as they don’t harm the host,they aren’t a nuisance, but how do we classify them??

Living together in a chaotic world.

• Symbiosis: living together for a common benefit. (Symbiont smaller, host larger).

• Commensalism: one animal lives on another, but doesn’t harm it.

• Parasitism: one does benefit (host doesn’t).

Ecosystem Organization

Marine environment is divided by distance from land, depth and the type of organisms living there.

Figure 10.14

Trophic Pyramids

Figure 10.17

Figure 10.18

Figure 10.19

Figure 10.20

Figure 10.21

Figure 10.22

Text Art 10.01

Text Art 10.02

Table 10.01