<p>They look like stone fish traps or <a href="https://en.wikipedia.org/wiki/Fishing_weir" rel="noreferrer">weirs</a>. They are used by native poeple to catch fish on a large scale.  They can actually vary quite a bit by culture and can be quite large.  Here is a stone and wood one with the same shape</p>

<p><a href="https://i.sstatic.net/LLFtr.jpg" rel="noreferrer"><img src="https://i.sstatic.net/LLFtr.jpg" alt="enter image description here"></a></p>

CC BY-SA 3.0
2017-06-02T03:41:31.823Z
2017-06-02T03:41:31.823Z
John
<p>Those are Yap Traditional Fish Weirs, according to <a href="http://www.islandculture.info/yaptraditionalfishweirs/index.htm" rel="noreferrer">islandculture.info</a></p>

<blockquote>
  <p>In 2008, Yap State Historic Preservation Office (YSHPO) commenced a
  project to survey the fish weirs (aech) around the main island of Yap.
  The aech is a stone/rock structure, usually in the shape of an arrow
  (many have a shaft, some do not), that catch fish after they move
  inside a catchment area at high tide and are trapped when the tide
  goes out. It is thought 700-800 aech may be located around Yap's main
  island which has a coastline of about 100 km in circumference.
  <a href="https://i.sstatic.net/MSeDA.jpg" rel="noreferrer"><img src="https://i.sstatic.net/MSeDA.jpg" alt="Yap traditional fish weirs"></a></p>
</blockquote>

CC BY-SA 3.0
2017-06-02T03:52:06.113Z
2017-06-02T03:52:06.113Z
jeffronicus
<p>Looks like it has something to do with fishing: <a href="https://www.google.com/maps/place/9%C2%B032&#39;00.9%22N+138%C2%B011&#39;20.8%22E/@9.5339863,138.1891537,543m/data=!3m1!1e3!4m5!3m4!1s0x0:0x0!8m2!3d9.5335853!4d138.1890973" rel="noreferrer">Google maps link</a></p>

<p><a href="https://i.sstatic.net/GhRS1.jpg" rel="noreferrer"><img src="https://i.sstatic.net/GhRS1.jpg" alt="enter image description here"></a></p>

<human-influence>
What are those arrowlike underwater structures for?
ZuOverture
# What are those arrowlike underwater structures for?

(Asked by: username_0 on 2017-06-01)

Looks like it has something to do with fishing: [Google maps link](https://www.google.com/maps/place/9%C2%B032'00.9%22N+138%C2%B011'20.8%22E/@9.5339863,138.1891537,543m/data=!3m1!1e3!4m5!3m4!1s0x0:0x0!8m2!3d9.5335853!4d138.1890973)

[![enter image description here](https://i.sstatic.net/GhRS1.jpg)](https://i.sstatic.net/GhRS1.jpg)

**Tags:** human-influence


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## 2 answers

### Answer by username_2 on 2017-06-02. Score: 14 | Accepted answer

Those are Yap Traditional Fish Weirs, according to [islandculture.info](http://www.islandculture.info/yaptraditionalfishweirs/index.htm)

> In 2008, Yap State Historic Preservation Office (YSHPO) commenced a
> project to survey the fish weirs (aech) around the main island of Yap.
> The aech is a stone/rock structure, usually in the shape of an arrow
> (many have a shaft, some do not), that catch fish after they move
> inside a catchment area at high tide and are trapped when the tide
> goes out. It is thought 700-800 aech may be located around Yap's main
> island which has a coastline of about 100 km in circumference.
> [![Yap traditional fish weirs](https://i.sstatic.net/MSeDA.jpg)](https://i.sstatic.net/MSeDA.jpg)


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### Answer by username_1 on 2017-06-02. Score: 9

They look like stone fish traps or [weirs](https://en.wikipedia.org/wiki/Fishing_weir). They are used by native poeple to catch fish on a large scale. They can actually vary quite a bit by culture and can be quite large. Here is a stone and wood one with the same shape

[![enter image description here](https://i.sstatic.net/LLFtr.jpg)](https://i.sstatic.net/LLFtr.jpg)


---

