Question

If we were taking salinity readings from an area in an estuary where a river is flowing into the ocean water, we would find the freshest water at the surface. This is true because freshwater is

more dense than saltwater

less dense than saltwater

colder than the saltwater

a better solvent than saltwater

Answer 1

Ok again, which one do you think it is?

Answer 2

the last one ?

Answer 3

What makes you say that?

Answer 4

This question is saying that one floats on the top, the other one is at the bottom. What does having more salt at the bottom of the sea do to it?

Answer 5

would it let it float better

Answer 6

Ok try this:

What makes one thing float? Why is it that some objects float while some sink?

Answer 7

it has alot of weight so it will be the 1st answer

Answer 8

Things float because they are less dense than water correct?

Answer 9

If freshwater is more dense than water would it sink or float?

Answer 10

float

Answer 11

Whoops that question was mean to say:
'If freshwater is more denser than sea water would it float or sink?'.
You said it would float. That is correct.

Now, in the question, where is the freshwater?

Answer 12

In your question you posted.

Answer 13

surface

Answer 14

So that means?

Answer 15

its floating

Answer 16

So what's the answer?

Answer 17

more dense the 1st one

Answer 18

Are you saying that freshwater is more dense than seawater?

Answer 19

yes im WRONG HUH :(

Answer 20

Well think about this.

We found that things less dense float on things more dense. Like how a balloon (not very dense) floats on water (more dense).

Now you just told me that freshwater floated (on salt water). Which is more dense?

Answer 21

salt water , which means its the 2nd one

Answer 22

Correct!

It turns out that salt water is more dense because salt is quite heavy, so adding it to water increases it's density!

A rock sinks because it is more dense than water. A balloon floats because it is less dense than water. Freshwater floats because it is less dense than salt water. Is this ok with you? Reread the question.

Answer 23

The reason why we can get salt water in the first place relies on the property that it is a good solvent. But the fourth option doesn't directly explain WHY FRESHWATER FLOATS. It is the density that does this.

Answer 24

wow that makes sense

Answer 25

thanks

Answer 26

Rachel Carson wrote about the delicate balance of organisms in a food web. Snakeheads, a freshwater fish that is not normally found in the United States, was accidentally introduced to the Potomac River, which flows into the Chesapeake Bay. As a juvenile the Snakehead would feed on zooplankton and small crustaceans.. At the juvenile stage, its predator would only be large predatory fish. Consider the food web below how could a similar organism potentially affect the ecosystem?

Answer 27

Lol I typed up a response before and then it somehow disappeared. I will type it up again.

Answer 28

k lol thanks

Answer 29

The point of this question is probably to get you to talk about two main things:
1. The cycle (therefore the picture).
2. Disruption of that cycle by introducing something new to that particular ecosystem.

The cycle is a very important point in that ecosystem. When you take something out, it can do harm, when you put something in, it can do harm. But I guess the thing here is that we aren't so sure how much harm it can do without actually seeing it in action. Maybe you can talk about how we aren't sure how much damage/effects/harm it can do until it actually does infect as the introduction.

Then you can move on to talking about the general harm we would expect though (but we can't make too many statements about how MUCH harm it can do, just that if it can happen or not.

Introducing the snakehead (or something similar) into that ecosystem, it may eat a lot of the zooplankon, which may lead to a drop in the zooplankton. If we refer to the graph, this can potentially reduce the small fish and crustaceans because now they are in competition for the resources. Also, as the zooplankton are in lower numbers, they don’t feed on as much phytoplankton in general, so the levels may increase.

It was noted that large fish feed on small fish and crustaceans. Now because those have decreased, that may decrease the large fish as well, which may then decrease the marine mammals. They did mention that during the juvenile stages, the snakehead would only be eaten by LARGE PREDATORY FISH. So that might help with the large predatory fish numbers, but what happens when the snakehead is no longer juvenile? Wouldn’t it potentially be in competition with the large predatory fish therefore posing more problems to it? Then wouldn’t it then feed on a lot of the small fish (possibly, I don’t know if it does this but it might) therefore decreasing the small fish population even more and disrupting the ecosystem even more? There is a potential for destroying the ecosystem, and even in some situations, the wiping out of particular species in the area. Things like this have happened before, and if humans see it (often humans are the source of a lot of these problems), they can try to fix it, that’s why there are intervention programs.
The point here I would like to make is that there is a cycle that occurs in the ecosystem. This cycle is very dependent on each member, and disruption could do a lot of harm. The statements I have made are just possibilities, but we can’t actually know for 100% sure if this would happen to a super large degree unless it actually does happen. It might even be that it doesn’t affect it that much.

Answer 30

I would recommend that you refer to what you have learned in class and what your teacher prefers. Because different teachers have different preferences, and can teach different things so to include things specifically to what he/she wants in an answer is important. I do not have much of an idea on what you or your teacher likes so I have included just some ideas.

Answer 31

your very brilliant in this subject thankssss

Answer 32

your explanation explains it very well

Answer 33

Also talk about how if there is very little blockage of the snakehead, like if it doesn't have many predators and if it is good competition, it can wipe out it's competition. Wiping out its competition also might help bring the zooplankton level back up (along with the idea that because the zooplankton levels dropped in the first place the phytoplankton levels increased), now it can feed, breed and thrive in that area.

Answer 34

Thank you!

I can't be 100% sure if this is what you need or this is even right though.

Answer 35

As an environmental engineer, you decide to create the globes largest Mangrove forest in Florida. Mangrove forest provide.

improved water quality.
habitats for marine organisms.
nursery area for fish and crustaceans.

all of the above.

Answer 36

What do you know about mangroves?

Answer 37

its a tree

Answer 38

Sorry about that, had some Internet issues, now it seems to be fine. Anything else :)?

That you know about mangroves?

Answer 39

its ok and that it grow in saline coastal

Answer 40

Ok. What answer do you think it is?

Answer 41

all of the above

Answer 42

Correct! (Internet issue again). They help to filter the water. They provide an environment for marine life. Etc. Also you can plant them near the sides of islands to help with water level control, because they absorb a lot of water so keep the sea levels down.

Answer 43

thanks
Which statement best explains what happens to energy in a food chain?

The amount of energy increases as you move up a food chain because each organism adds energy.

The amount of energy increases as you move up a food chain because the organisms consume more food.

The amount of energy decreases as you move up a food chain because each organism uses some of the energy.

The amount of energy does not change as you move up a food chain because each organism replenishes the energy it uses.

Answer 44

When an organism down the food chain is eaten, not all of the energy eaten goes directly into energy that the next up the food chain can take. I mean some of the energy that is gained by eating is used in digestion, some cannot be digested, some is in general used by the organism to survive eg. to keep warm etc.

The only energy 'available' for the organism next up the food chain to consume is what out of the food it consumes gets into storage or making other parts of its body.

So energy is _______ as you go up.

Answer 45

increase

Answer 46

Let's say that an organism A eats organism B, and gets 100 calories. Lots of this energy is 'lost', during digestion, 'lost' in general as heat etc. In the end, only 10 might be stored. So when C eats A, it gets organism A + 10 calories from B.

So what was originally 100 becomes 10. The next along the chain becomes a smaller amount and so forth. What is the answer?