user16866: Not many casual biologists (and certainly very few non-biologists) know what the field of limnology refers to. As such, I would think that a number of questions that would appropriately receive the limnology tag have not (and do not) receive the tag. (e.g., a search for "lake" brings up 82 results that otherwise have no limnological tag associated with them).  
So I proposed two tag synonyms for limnology

aquatic-biology
freshwater-biology

My reasoning was to allow someone searching for tags referencing two well known terms ("freshwater" and/or "aquatic") to get to the appropriate limnology tag.  
I was assuming that suggesting these tag synonyms was the appropriate way to do this. However, I had to create these two new tags in order to actually suggest them as synonyms. Is there a different way to propose "synonyms" for improving the ability to search for appropriate tags without having to create new tags? In other words, can a non-existent tag synonym just be added directly to an existing tag?  

user16866: Suggested Solution:
As discussed in this Q&A's comments and in fileunderwater's post, I think the best thing to do moving forward is:

freshwater-biology should be made the main tag (i.e., the "master") and limnology be made a synonym.
I think an aquatic-biology tag would be ok to keep in instances where water in general (i.e., irrespective of marine vs fresh) is the focus.

This tag should not be made a synonym of either freshwater-biology or marine-biology. (In other words, my synonym suggestion for aquatic-biologyshould be deleted -- can I do that myself??). 


Approach:
I suggested these tag edits over a month ago, but only 1 other member seems to have high enough rep in limnology to vote on the pending tag suggestion. However, a few members discussed these suggestion here in meta, and we seem to be in agreement about how to move forward with these tags.
Can I ask one of the current mods (@Chris, @WYSIWYG, @MadScientist) to make these changes?
I'm very certain that the freshwater-biolgy tag could be assigned to numerous existing questions and would be very useful to new users (especially since few people know what limnology is). 

I think we should "clean this up" sooner than later to help us better assign water-related posts the appropriate tags. 


user3624: I see the point of joining limnology and freshwater-biology, since they are so close to each other (as @BryanKrause points out, limnology is a bit broader though). However, freshwater-biology is sort of the parallel to the existing (and useful) tag marine-biology (so maybe freshwater-biology should be the "main" tag?). Placing aquatic-biology as a synonym isn't really appropriate though, since it is much broader than limnology (can cover to both limnology, marine biology and freshwater biology).
All in all, I think making freshwater-biology a synonym is a good idea - people can still search for and use that tag (in relation to marine-biology), but it will be reclassified as limnology.

16866: <p>Not many casual biologists (and certainly very few non-biologists) know what the field of <a href="https://biology.stackexchange.com/questions/tagged/limnology" class="post-tag" title="show questions tagged &#39;limnology&#39;" rel="tag">limnology</a> refers to. As such, I would think that a number of questions that would appropriately receive the <a href="https://biology.stackexchange.com/questions/tagged/limnology" class="post-tag" title="show questions tagged &#39;limnology&#39;" rel="tag">limnology</a> tag have not (and do not) receive the tag. (e.g., a search for "lake" brings up 82 results that otherwise have no limnological tag associated with them).  </p>

<p>So I proposed two tag synonyms for <a href="https://biology.stackexchange.com/questions/tagged/limnology" class="post-tag" title="show questions tagged &#39;limnology&#39;" rel="tag">limnology</a></p>

<ul>
<li>aquatic-biology</li>
<li>freshwater-biology</li>
</ul>

<p>My reasoning was to allow someone searching for tags referencing two well known terms ("freshwater" and/or "aquatic") to get to the appropriate <a href="https://biology.stackexchange.com/questions/tagged/limnology" class="post-tag" title="show questions tagged &#39;limnology&#39;" rel="tag">limnology</a> tag.  </p>

<p>I was assuming that suggesting these tag synonyms was the appropriate way to do this. However, I had to create these two new tags in order to actually suggest them as synonyms. Is there a different way to propose "synonyms" for improving the ability to search for appropriate tags without having to create new tags? In other words, can a non-existent tag synonym just be added directly to an existing tag?  </p>
 16866: <p><strong>Suggested Solution:</strong></p>

<p>As discussed in this Q&amp;A's comments and in fileunderwater's post, I think the best thing to do moving forward is:</p>

<ol>
<li><p><strong><a href="https://biology.stackexchange.com/questions/tagged/freshwater-biology" class="post-tag" title="show questions tagged &#39;freshwater-biology&#39;" rel="tag">freshwater-biology</a> should be made the main tag (i.e., the "master") and <a href="https://biology.stackexchange.com/questions/tagged/limnology" class="post-tag" title="show questions tagged &#39;limnology&#39;" rel="tag">limnology</a> be made a synonym.</strong></p></li>
<li><p>I think an <a href="https://biology.stackexchange.com/questions/tagged/aquatic-biology" class="post-tag" title="show questions tagged &#39;aquatic-biology&#39;" rel="tag">aquatic-biology</a> tag would be ok to keep in instances where water in general (i.e., irrespective of marine vs fresh) is the focus.</p>

<ul>
<li>This tag should not be made a synonym of either <a href="https://biology.stackexchange.com/questions/tagged/freshwater-biology" class="post-tag" title="show questions tagged &#39;freshwater-biology&#39;" rel="tag">freshwater-biology</a> or <a href="https://biology.stackexchange.com/questions/tagged/marine-biology" class="post-tag" title="show questions tagged &#39;marine-biology&#39;" rel="tag">marine-biology</a>. (In other words, <strong>my synonym suggestion for <a href="https://biology.stackexchange.com/questions/tagged/aquatic-biology" class="post-tag" title="show questions tagged &#39;aquatic-biology&#39;" rel="tag">aquatic-biology</a>should be deleted</strong> -- can I do that myself??). </li>
</ul></li>
</ol>

<p><strong>Approach:</strong></p>

<p>I suggested these tag edits over a month ago, but only 1 other member seems to have high enough rep in <a href="https://biology.stackexchange.com/questions/tagged/limnology" class="post-tag" title="show questions tagged &#39;limnology&#39;" rel="tag">limnology</a> to vote on the pending tag suggestion. However, a few members discussed these suggestion here in meta, and we seem to be in agreement about how to move forward with these tags.</p>

<p><strong>Can I ask one of the current mods (@Chris, @WYSIWYG, @MadScientist) to make these changes?</strong></p>

<p>I'm very certain that the <a href="https://biology.stackexchange.com/questions/tagged/freshwater-biolgy" class="post-tag" title="show questions tagged &#39;freshwater-biolgy&#39;" rel="tag">freshwater-biolgy</a> tag could be assigned to numerous existing questions and would be very useful to new users (especially since few people know what <code>limnology</code> is). </p>

<ul>
<li>I think we should "clean this up" sooner than later to help us better assign water-related posts the appropriate tags. </li>
</ul>
 3624: <p>I see the point of joining <a href="https://biology.stackexchange.com/questions/tagged/limnology" class="post-tag" title="show questions tagged &#39;limnology&#39;" rel="tag">limnology</a> and <a href="https://biology.stackexchange.com/questions/tagged/freshwater-biology" class="post-tag" title="show questions tagged &#39;freshwater-biology&#39;" rel="tag">freshwater-biology</a>, since they are so close to each other (as @BryanKrause points out, limnology is a bit broader though). However, <a href="https://biology.stackexchange.com/questions/tagged/freshwater-biology" class="post-tag" title="show questions tagged &#39;freshwater-biology&#39;" rel="tag">freshwater-biology</a> is sort of the parallel to the existing (and useful) tag <a href="https://biology.stackexchange.com/questions/tagged/marine-biology" class="post-tag" title="show questions tagged &#39;marine-biology&#39;" rel="tag">marine-biology</a> (so maybe <a href="https://biology.stackexchange.com/questions/tagged/freshwater-biology" class="post-tag" title="show questions tagged &#39;freshwater-biology&#39;" rel="tag">freshwater-biology</a> should be the "main" tag?). Placing <a href="https://biology.stackexchange.com/questions/tagged/aquatic-biology" class="post-tag" title="show questions tagged &#39;aquatic-biology&#39;" rel="tag">aquatic-biology</a> as a synonym isn't really appropriate though, since it is much broader than limnology (can cover to both limnology, marine biology and freshwater biology).</p>

<p>All in all, I think making <a href="https://biology.stackexchange.com/questions/tagged/freshwater-biology" class="post-tag" title="show questions tagged &#39;freshwater-biology&#39;" rel="tag">freshwater-biology</a> a synonym is a good idea - people can still search for and use that tag (in relation to <a href="https://biology.stackexchange.com/questions/tagged/marine-biology" class="post-tag" title="show questions tagged &#39;marine-biology&#39;" rel="tag">marine-biology</a>), but it will be reclassified as limnology.</p>
