# how do Aquariums fill their huge tanks? **URL:** \ **Category:** Factual Questions\ **Created:** [May 27, 2014, 10:26pm UTC](https://boards.straightdope.com/t/how-do-aquariums-fill-their-huge-tanks/689415 "2014-05-27T22:26:27Z")\ **Posts on this page:** 4\ **Page:** 4
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [June 4, 2014, 6:19pm UTC](https://boards.straightdope.com/t/how-do-aquariums-fill-their-huge-tanks/689415/61 "2014-06-04T18:19:48Z")
> [@Xema](#): > > Your argument works equally well for roadblocks and inspections to insure that no one is carrying, say, vials of anthrax across state lines. Wouldn’t it make sense to take precautions against what could obviously be a very nasty threat? Because that’s not a realistic threat. People send that shit through the mail (where, surprise, it does get scanned for.) No-one’s been affected by massive outbreaks of human-carried anthrax moved across borders. Whereas they already have been affected by water-borne invasives. > [@](#): > > Well no, actually. The cost of such inspections and the actual rate at which people smuggle anthrax across state lines makes this idea quite silly. No-one’s suggesting setting up a Bureau of Seawater Tanker Inspections. Boats are already being checked on the Interstates, the tankers just join the queue. And all that’s got jack to do with the Precautionary Principle, by the way - the Principle says that in absence of scientific certainty either way (since no-one’s researched invasives in tankers yet AFAIK), the burden of proof is on _you_ to show that shipping seawater sea-to-sea is _not_ harmful. Expense arguments are irrelevant. Potential environmental harm is the only criterion. Which is _why_ I said you need to show that tankers differ somehow from provably harmful bilges. That’s how you show there’ll be no harm. C’mon, the Precautionary Principle is Environmental Science 101 stuff. You might want to get more familiar with it if you’re going to advocate ignoring sensible environmental protections just because it might cost a few bucks. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [June 4, 2014, 7:25pm UTC](https://boards.straightdope.com/t/how-do-aquariums-fill-their-huge-tanks/689415/62 "2014-06-04T19:25:13Z")
> [@Colophon](#): > > Not if you’re trucking it to Las Vegas casinos. Obviously they want to stop any sea life from colonising the desert. The ocean is a desert, with its life underground, And the perfect disguise above. (I don’t know how everyone missed that… 🙂 ) The invasive species problem happens because freighters would take on bilge water as ballast, and then pump it out at inopportune times, dumping hitchhikers in novel locations. This is supposedly how zebra mussels got started in the Great Lakes. They spread around the smaller lakes hitching rides now on or in the bilge of small boats that arrive by trailer from infected lakes. A lot of freighters, too, were in the habit of relieving themselves of oil-contaminated bilge water, thus leaving oil slicks where they ended up. As regulations were tightened, Canada started to find these slicks offshore as the freighters waiting until they thought they were beyond detection before doing a cleansing cycle. So journeying up and down a coastline into open ports probably does not matter. What’s on the hull and not killed by the journey probably is already there at the destination and does not matter. Coming from a distant and different ecosystem and potentially carrying quantities of unfiltered water from there is grounds for concern. ---
**Author:** ![Hermitian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hermitian/32/470_2.png) [@Hermitian](https://boards.straightdope.com/u/Hermitian)\ **Post date:** [June 4, 2014, 7:57pm UTC](https://boards.straightdope.com/t/how-do-aquariums-fill-their-huge-tanks/689415/63 "2014-06-04T19:57:49Z")
Everyone is talking about inspecting a tanker of seawater. Um… how in the world would you do that? You think the inspection site has a scuba diver on hand to search the whole tank? Am I missing something? ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [June 5, 2014, 5:56am UTC](https://boards.straightdope.com/t/how-do-aquariums-fill-their-huge-tanks/689415/64 "2014-06-05T05:56:02Z")
> [@Hermitian](#): > > Everyone is talking about inspecting a tanker of seawater. Um… how in the world would you do that? > > You think the inspection site has a scuba diver on hand to search the whole tank? Am I missing something? Tankers have drawdown outlets to remove samples. If something’s in the tank water, like larvae or algae, you would see it in a jugfull, too. [Previous page](https://boards.straightdope.com/t/how-do-aquariums-fill-their-huge-tanks/689415.md?page=3)