1.0LHEIhttps://lhei.lv/en/valentinahttps://lhei.lv/en/author/valentina/rich600338<blockquote class="wp-embedded-content" data-secret="GCm28NP0jZ"><a href="https://lhei.lv/en/water-transparency/">Water transparency</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://lhei.lv/en/water-transparency/embed/#?secret=GCm28NP0jZ" width="600" height="338" title="“Water transparency” — LHEI" data-secret="GCm28NP0jZ" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(d,l){"use strict";l.querySelector&&d.addEventListener&&"undefined"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i<o.length;i++)o[i].style.display="none";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute("style"),"height"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):"link"===t.message&&(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document); //# sourceURL=https://lhei.lv/wp-includes/js/wp-embed.min.js </script> https://lhei.lv/wp-content/uploads/2023/10/800x640-udenscaur.png800640Summer water transparency (Secchi depth) observations in the open waters of the Gulf of Riga are available from 1963, in transitional waters from 1983, in coastal waters of the Gulf of Riga from 1991 and in coastal waters of the Baltic Sea from 1999.